Maurice Lacroix band size chart by reference

Maurice Lacroix is a fit-list brand, not a width brand. The Aikon family runs a half-millimetre width ladder, 20, 23, 23.5, 24 and 25 mm [24] [5] [10] [28], and almost every Aikon strap prints Straight strap mount: No, the dealer network's own wording for: this strap only fits the references in its list, and a generic strap will not mount [1]. Pontos and Fiaba are the opposite: their straps print Straight strap mount: Yes in standard widths (15 to 24 mm) and take any good generic strap of the right width [31] [45]. Every row below is built from the spec blocks of official Maurice Lacroix dealers (auer.lu, hollandwatchgroup.com, watch.co.uk, mastersintime.com) with the brand's own product pages where they surface, each row checked on at least two independent surfaces.

Quick answers: Aikon 42mm automatic and 44mm chronograph take 25mm original straps (no straight mount, generic straps do not fit). Aikon 45mm Master Grand Date takes 24mm rubber per dealers, 25mm per the brand's own page. Aikon 39mm automatic takes 23mm. Aikon 40mm quartz takes 23mm. 23.5mm is a real size (red rubber ML640-005014). Pontos: 20mm (PT6148/6158/6168/6208/6358/6368), odd 21mm (PT6178/6188/7558), 24mm (PT6217/6237/6257/6009), all straight mount, generic OK. Fiaba current 18mm, vintage 15mm, straight mount. The case code on your caseback (AI6008, PT6158) is the search key, not the case diameter.

The one field that decides everything: Straight strap mount

Official Maurice Lacroix dealers publish a fixed spec block for every original strap: Strap width, Lug width, Band width at clasp, lengths at 12 and 6 o'clock, Mount type, and a yes/no line called Straight strap mount. That last line is the whole compatibility question. When it reads Yes, the strap is cut straight and, in the dealers' own words, "is suitable for all Maurice Lacroix watches with a straight mount" [31]: any generic 20, 21 or 24mm strap of decent quality mounts the same way. When it reads No, the dealer text says the strap "is only suitable for the watches listed below" [1], and the fit list that follows is exhaustive. No dealer prints this rule in one place across the brand; this chart does. If your Maurice Lacroix is an Aikon, assume No until its reference shows otherwise, and buy by part number. If it is a Pontos or Fiaba, measure between the lugs and any matching generic strap works; the how to measure guide covers the 30-second check.

The chart: 16 verified rows

The Strap x Clasp column is the pair printed in the dealer spec blocks (width at the case end x width at the clasp). The Mount column is the printed Straight strap mount flag, which is also the original-versus-generic verdict. Fit lists are quoted from the dealer pages for the part numbers shown; where the brand's own site prints a different width for the same reference, the conflict is in the row, not hidden. Type a case code or family to filter.

Maurice Lacroix band width by reference and part number
Watch / referencesCaseStrap x ClaspMountOriginal part and notes
Aikon Automatic Chronograph (AI6058-SS001-430-1, AI6058-SS002-430-2)44 mm25 x 20 mmNo (pushpins)ML640-005006 blue silicone, 13 mm lug field, 75/115 mm lengths; fit list names exactly these two references [1] [2] [3] [4]
Aikon Automatic 42mm (AI6008-SS000-130-2, AI6008-SS00B-130-G, AI6008-SS00F-130-A)42 mm25 x 20 mmNo (quick release)ML640-005018 grey rubber, 13.3 mm lug field, 75/120 mm; brand's own ML822-005018 prints 25 mm for AI1118/AI6008/AI6058/AI6158 [5] [6] [7]
Aikon Automatic 42mm, light blue variant (AI6008-SS00F-431-C)42 mm25 x 20 mmNo (quick release)ML640-005078 light blue rubber, 13 mm lug field, 75/115 mm [8] [9]
Aikon Master Grand Date (AI6118, e.g. AI6118-DLB0J-430-H)45 mm24 x 18 mmNo (quick release)ML640-005039 blue rubber, 13 mm lug field; CONFLICT: the brand's own product page prints 25 mm rubber and the 24mm steel bracelet shares the case, so match the part to the reference [10] [11] [12] [13] [14]
Aikon Automatic 39mm (AI6007, AI6007-SS000-430-4, AI6007-SS00F-430-C)39 mm23 x 18 mmNo (quick release)ML640-005031 blue silicone, 12.5 mm lug field, 75/115 mm; the brand's own 39mm page prints STRAP WIDTH 23 mm [19] [20] [22]
Aikon Automatic 39mm blue PVD limited (AI6007-PVC00-430-4)39 mm23 x 18 mmNo (quick release)ML640-005090 blue rubber, 12.5 mm lug field, 75/110 mm; the watch's own page names it the original strap and fits wrists 160-210 mm [15] [16]
Aikon Automatic 39mm, light blue (AI6007-SS00F-431-C)39 mm23 x 18 mmNo (quick release)ML640-005077 light blue rubber, 12.5 mm lug field, 75/115 mm [17] [18]
Aikon Quartz Date 40mm (AI1108 class)40 mm23 mm (watch page)Nothe brand's own AI1108 page prints WIDTH 23 mm; the ML822-005031 rubber accessory claims AI1108 compatibility at 24 mm, and dealer fit lists put ML640-005031 (23 mm) on AI1108 too: order by reference, not by either rounded width [21] [23] [49] [50]
Aikon 35mm class, red rubber (ML640-005014)35 mm class23.5 x 18 mmNo (quick release)the half-millimetre rung: 13 mm lug field, 75/115 mm; resale listings show 23.5 mm factory straps on AI1018 references [24] [25] [26] [27]
Aikon, narrowest rung (ML640-005075)small case20 mmNo (quick release)light blue rubber, 11 mm lug field, 75/115 mm; the narrowest Aikon strap in the dealer network, fit list not published on the surfaced pages, so verify by reference before ordering [28] [29] [30]
Pontos (PT6148, PT6158, PT6168, PT6208 and variants)40-43 mm20 x 18 mmYes (pushpins)ML550-005001 alligator, 20/20 strap and lug fields, 90/105 mm; straight mount, generic 20mm straps fit [31] [32] [33]
Pontos (PT6178, PT6188, PT7558 and variants)41-43 mm21 x 18 mmYes (pushpins)ML550-000200 crocodile, 21/21 fields, 80/115 mm; the odd 21mm width, understocked in the generic trade [34] [35] [36]
Pontos (PT6358, PT6368 and variants)40-41 mm20 x 18 mmYes (pushpins)ML800-005002 calf alligator-print, 20/20 fields, 3.3 mm thick, 75/115 mm [37] [38] [39]
Pontos (PT6217, PT6237, PT6257)43 mm class24 x 18 mmYes (pushpins)ML550-000191 crocodile, 24/24 fields, 90/120 mm [40] [41]
Pontos (PT6009-SS001-330)43 mm class24 x 20 mmYes (pushpins)ML740-000066 calf leather, 24/24 fields, 4.5 mm thick, 80/120 mm [42] [43]
Fiaba current (FA1205 Square and Round)32-34 mm18 x 16 mmYes (quick release)ML823-005155 class calf straps, 18/18 fields; the brand's own FA1205 page and strap store print 18 mm [44] [45] [46]

Vintage Fiaba note: older FA2084/FA2104/FA2124/FA2154 references take 15 x 12 mm straps (ML555-000018 crocodile class, 70/100 mm), straight mount, confirmed on two dealer surfaces [47] [48].

The half-millimetre ladder: 23, 23.5, 24, 25 on near-identical rubber

The Aikon strap program looks uniform and is not. Four blue rubber straps for four different Aikons print, in the same dealer spec-block format: 25 mm for the 42mm automatic (ML640-005018, with a 13.3 mm lug field) [5], 24 mm for the 45mm Master Grand Date (ML640-005039) [10], 23.5 mm for the red rubber (ML640-005014) [24] and 23 mm for the 39mm automatic (ML640-005031) [19]. A millimetre and a half separates the widest from the narrowest, and nothing on the watch's exterior tells you which you have: the caseback code does. That is why every dealer fit list keys on the AIxxxx reference, and why this chart does too. The taper also varies inside one width class: most 23mm Aikon straps taper to 18mm at the clasp, while the 25mm straps taper to 20mm [17] [1]; the strap taper guide explains why that matters when you buy a replacement buckle, which Maurice Lacroix sells separately on most of these parts.

Two places the sources disagree, and what to do

Two rows carry a live width conflict, and both are better known than ignored. First, the 45mm Master Grand Date AI6118: all three dealer surfaces give its blue silicone strap as 24 mm [10] [11] [12], while the brand's own product page for AI6118-DLB0J-430-H prints WIDTH 25 mm for its rubber straps [13], and the same case carries a 24mm steel bracelet [14]. Second, the 40mm quartz AI1108: the brand's own watch page prints 23 mm [23], but the brand's ML822-005031 rubber accessory claims AI1108 compatibility at 24 mm [21], and a French dealer titles the same-numbered ML640-005031 part 24 mm [50] while the official dealer fit list puts that 23 mm part on AI6007 and AI1108 watches [49]. In both cases the resolution is the same: the part number's fit list beats every rounded width, including the brand's own. Email the dealer a photo of the caseback if your reference is not in a list; that is what the dealers themselves ask for [4].

Pushpins, quick release, and what the Lug width field means

Two mount generations run through the Aikon program. The older 44mm chronograph straps (ML640-005006) mount on plain pushpins: releasing them takes a spring-bar tool or a fine pin push. Everything newer, from the 39mm automatics to the 42mm and 45mm rubbers, mounts on quick release pushpins, with a sliding pin in the strap end so the swap is tool-free [5] [17]; the brand calls its version the Easy change system and prints "Easy change system available: Yes" on current watch pages [22]. The spec block's Lug width field tracks this hardware: on straight-mount Pontos and Fiaba straps it equals the strap width (21/21, 20/20, 18/18) [34] [45], but on Aikon parts it reads 11, 12.5, 13 or 13.3 mm [28] [19] [1] [5]: that is the shaped mounting end that sits in the case, not the strap width you order by. The spring bar sizes guide and the tool guide cover the actual swap; the lug width chart places these widths against every other brand.

Pontos and Fiaba owners: you have it easy

If your Maurice Lacroix caseback starts PT or FA, the whole question reduces to a measured width. Every Pontos and Fiaba original strap in the dealer network prints Straight strap mount: Yes [31] [40] [47], which is the trade's mark for a standard straight-cut band on ordinary spring bars. Measure between the lugs (20, 21, 24 or 18mm, 15mm on the vintage ladies' pieces), pick any strap of that width with the right taper, and it mounts. The only genuine trap is the 21mm Pontos width [34]: it is half the reason PT6178/PT6188 owners end up on this page, because 21mm is the least-stocked even size in the generic strap trade. If your local shop has nothing, a 20mm strap on a 21mm lug is a poor fit; order the 21mm original (ML550-000200 class) or a made-to-21mm aftermarket band instead.

Related guides

Once the width is settled: the strap taper guide explains the 25-to-20 and 23-to-18 tapers that dominate this brand, the lug width chart is the all-brand width index, and how to measure is the 30-second check that beats any chart including this one. The band size chart covers the generic 14-26mm trade sizes these widths slot into. For sibling brand charts: Tag Heuer, Baume & Mercier, Bulova, Nomos, Oris and Movado.

Sources

  1. Auer.lu, official Maurice Lacroix dealer, ML640-005006 Aikon strap spec block: Strap width 25 mm, Lug width 13 mm, Band width at clasp 20 mm, lengths 75/115 mm, Mount type Pushpins, Straight strap mount No, fits AI6058-SS001-430-1 and AI6058-SS002-430-2: auer.lu
  2. Watch.co.uk, same dealer network, ML640-005006: identical fields: watch.co.uk
  3. Hollandwatchgroup.com, ML640-005006: identical fields: hollandwatchgroup.com
  4. Mastersintime.com, ML640-005006: identical fields; the dealer strap-finder asks for the caseback code and states non-straight-mount straps are found via customer service with a photo of the watch: mastersintime.com
  5. Watch.co.uk, ML640-005018 Aikon grey rubber: Strap width 25 mm, Lug width 13.3 mm, clasp 20 mm, lengths 75/120 mm, Quick release pushpins, Straight strap mount No, fits AI6008-SS000-130-2, AI6008-SS00B-130-G, AI6008-SS00F-130-A: watch.co.uk
  6. Mastersintime.com, ML640-005018: identical fields and fit list: mastersintime.com
  7. Maurice Lacroix official site, ML822-005018 LIGHT GREY RUBBER STRAP: WIDTH 25 mm, Easy change system Yes, compatible with AI1118, AI6008, AI6058 and AI6158 references: mauricelacroix.com
  8. Auer.lu, ML640-005078 Aikon light blue rubber with logo: 25 mm, Lug width 13 mm, clasp 20 mm, 75/115 mm, quick release, Straight strap mount No: auer.lu
  9. Mastersintime.com, ML640-005078: identical fields, fits AI6008-SS00F-431-C: mastersintime.com; Watch.co.uk, same part, identical: watch.co.uk
  10. Watch.co.uk, ML640-005039 Aikon blue silicone: Strap width 24 mm, Lug width 13 mm, clasp 18 mm, quick release, Straight strap mount No, fits AI6118-DLB0J-430-H: watch.co.uk
  11. Mastersintime.com, ML640-005039: identical fields: mastersintime.com
  12. Hollandwatchgroup.com, ML640-005039: identical fields: hollandwatchgroup.com
  13. Maurice Lacroix official site, AI6118-DLB0J-430-H Aikon Master Grand Date product page: STRAP WIDTH 25 mm on its blue and black rubber straps, pin buckle, Easy change Yes: mauricelacroix.com
  14. Mastersintime.com, AI6118-SS00E-430-C Aikon Master Grand Date watch page: 45 mm case, steel bracelet Strap width 24 mm, Lug width 13 mm, butterfly clasp, quick release: mastersintime.com
  15. Auer.lu, AI6007-PVC00-430-4 Aikon 39mm blue PVD watch page: original strap ML640-005090, Strap width 23 mm, Lug width 12.5 mm, clasp 18 mm, 75/110 mm, quick release, Straight strap mount No, fits wrists 160-210 mm: auer.lu
  16. Watch.co.uk, ML640-005090 strap page: 23 mm, Lug width 12.5 mm, clasp 18 mm, 75/110 mm, quick release, No: watch.co.uk
  17. Auer.lu, ML640-005077 Aikon light blue rubber: 23 mm, Lug width 12.5 mm, clasp 18 mm, 75/115 mm, quick release, No, fits AI6007-SS00F-431-C: auer.lu
  18. Watch.co.uk, ML640-005077: identical fields, fit list AI6007, AI6007-SS00F-431-C: watch.co.uk
  19. Auer.lu, ML640-005031 Aikon blue silicone: 23 mm, Lug width 12.5 mm, clasp 18 mm, 75/115 mm, quick release, No, fits AI6007, AI6007-SS000-430-4, AI6007-SS00F-430-C: auer.lu
  20. Hollandwatchgroup.com, ML640-005031: identical fields and fit list: hollandwatchgroup.com
  21. Maurice Lacroix official site, ML822-005031 BLUE RUBBER STRAP: WIDTH 24 mm, compatible with AI1108, AI6007 and AI6057 references, Easy change Yes (the 24mm sibling of the 23mm ML640-005031): mauricelacroix.com
  22. Maurice Lacroix official site, AI6007-SS002-130-1 Aikon Automatic Date 39mm product page: STRAP WIDTH 23 mm, Easy change system available Yes: mauricelacroix.com
  23. Maurice Lacroix official site, AI1108-SS002-430-1 Aikon Quartz Date 40mm product page: STRAP WIDTH 23 mm, Easy change system Yes: mauricelacroix.com
  24. Hollandwatchgroup.com, ML640-005014 Aikon red rubber: Strap width 23.5 mm, Lug width 13 mm, clasp 18 mm, 75/115 mm, quick release, Straight strap mount No: hollandwatchgroup.com
  25. Auer.lu, ML640-005014: identical fields: auer.lu
  26. Watch.co.uk, ML640-005014: identical fields: watch.co.uk
  27. eBay original-strap listings showing factory 23.5 mm Aikon straps on AI1018 references (red rubber, green leather, green rubber): ebay.com
  28. Auer.lu, ML640-005075 Aikon light blue rubber: Strap width 20 mm, Lug width 11 mm, 75/115 mm, quick release, Straight strap mount No: auer.lu
  29. Hollandwatchgroup.com, ML640-005075: identical fields: hollandwatchgroup.com
  30. Mastersintime.com, ML640-005075: identical fields: mastersintime.com
  31. Mastersintime.com, ML550-005001 Pontos alligator: Strap width 20 mm, Lug width 20 mm, clasp 18 mm, 90/105 mm, pushpins, Straight strap mount Yes, fits PT6148/PT6158/PT6168/PT6208 and variants: mastersintime.com
  32. Watch.co.uk, ML550-005001: identical fields, Straight strap mount YES: watch.co.uk
  33. Auer.lu, ML550-005001: identical fields and fit list: auer.lu
  34. Mastersintime.com, ML550-000200 Pontos crocodile: 21/21 mm strap and lug fields, clasp 18 mm, 80/115 mm, pushpins, Straight strap mount Yes, fits PT6178/PT6188/PT7558 and variants: mastersintime.com
  35. Hollandwatchgroup.com, ML550-000200: identical fields: hollandwatchgroup.com
  36. Auer.lu, ML550-000200: identical fields: auer.lu
  37. Mastersintime.com, ML800-005002 Pontos calf alligator-print: 20/20 mm fields, clasp 18 mm, 3.3 mm thick, 75/115 mm, pushpins, Straight strap mount Yes, fits PT6358/PT6368 and variants: mastersintime.com
  38. Auer.lu, ML800-005002: identical fields: auer.lu
  39. Hollandwatchgroup.com, ML800-005002: identical fields: hollandwatchgroup.com
  40. Mastersintime.com, ML550-000191 Pontos crocodile: 24/24 mm fields, clasp 18 mm, 90/120 mm, pushpins, Straight strap mount Yes, fits PT6217/PT6237/PT6257: mastersintime.com
  41. Auer.lu (German-language surface), ML550-000191: identical fields, Armbandbreite 24 mm, Ansatzbreite 24 mm, Gerade Bandhalterung Ja: auer.lu; Hollandwatchgroup.com, same part, identical: hollandwatchgroup.com
  42. Hollandwatchgroup.com, ML740-000066 Pontos calf: 24/24 mm fields, clasp 20 mm, 4.5 mm thick, 80/120 mm, pushpins, Straight strap mount Yes, fits PT6009-SS001-330-1: hollandwatchgroup.com
  43. Watch.co.uk, ML740-000066: identical fields: watch.co.uk
  44. Maurice Lacroix official site, ML823-005155 BLACK CALF LEATHER STRAP, Fiaba: WIDTH 18 mm, compatible with FA1205 references, Easy change Yes: mauricelacroix.com
  45. Auer.lu, ML823-L05155 Fiaba Square strap: Strap width 18 mm, Lug width 18 mm, clasp 16 mm, quick release pushpins, Straight strap mount Yes, fits FA1205-SS001-110-2: auer.lu
  46. Maurice Lacroix official site, FA1205-SS002-410-1 Fiaba Square product page: STRAP WIDTH 18 mm, Easy change Yes: mauricelacroix.com
  47. Mastersintime.com, ML555-000018 Fiaba shiny black crocodile: Strap width 15 mm, Lug width 15 mm, clasp 12 mm, 70/100 mm, quick release, Straight strap mount Yes, fits FA2084/FA2104/FA2124/FA2154: mastersintime.com
  48. Auer.lu, ML555-000018: identical fields and fit list: auer.lu
  49. Zegarki.zgora.pl dealer listing for ML640-005031 naming fit references AI6057, AI6007, AI1108: zegarki.zgora.pl
  50. Hece-International, ML640-005031 original Aikon rubber strap listed at 24 mm with Easy Change (the width-conflict second leg for the AI1108/AI6007 class): hece-international.com