Frederique Constant · Index
Strap for Index Automatic Stainless Steel / Silver
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-303WN5B6OS
FamilyIndex
MovementFrederique Constant caliber FC-303
Hours, Minutes, Seconds | Date
CaseStainless Steel
Straps for the Index FC-303WN5B6OS
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-303WN5B6OS, seen from the bench
The Frederique Constant Index FC-303WN5B6OS is a 40mm stainless steel watch with a 20mm lug width, representing contemporary accessible luxury watchmaking. It features the FC-303 automatic movement beating at 28,800 vibrations per second, with hours, minutes, seconds, and date window at 3 o'clock. The 316L steel case has a fixed bezel, screw-down crown, and 30-meter water resistance, combining clean Swiss design with legible minimalist dial and linear indices.
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