Frederique Constant · Index
Strap for Index Automatic Black
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
20mm
Lug width20 mm
Case diameter40 mm
ReferenceFC-303B5B6
FamilyIndex
MovementFrederique Constant caliber FC-303
Hours, Minutes, Seconds | Date
CaseStainless Steel
Straps for the Index FC-303B5B6
Selected for the 20 mm lug width · workshop selection
Vintage Black Calfskin Leather Strap€80
Hammered Calfskin Strap Light Blue€98
Hammered Calfskin Watch Strap Green with Ecru Stitching€98
Vintage Olive Green Calf Leather Watch Strap€80
Hammered Black Calfskin Strap — Ecru Stitching€98
The Index FC-303B5B6, seen from the bench
The Frederique Constant Index Automatic Black FC-303B5B6 is a 40mm stainless steel sports watch from the Index collection launched in 2004. It features the FC-303 automatic caliber with 38 hours of power reserve, a dark blue dial with white indices, and 30m water resistance. The watch measures 11mm thick and requires a 20mm lug width for proper proportional balance. The screw-down crown and sealed case represent refined Geneva watchmaking standards.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only