This strap utilizes "Blocked Integration" engineering, incorporating solid inserts for a flawless, motionless flush mount to the Deepsea case.Model: M107 VulchromaticCompatible with Rolex DeepseaMade in Switzerland of pure vulcanized rubber. No coating, blends or bondingMeets FDA and BVGG specifications: non-toxic, non-marking, non-allergenDurable and flexible. No distortion over time. Superior resistance to damage and exterior environmental elements (e.g. Ozone, UV and the harsh aggressions of an aquatic environment)Includes dual colored rubber straps made through VULCHROMATICTM patented dual-color technologyStandard fit for wrist sizes: XS-XL (6 - 81/4 inches or 15 - 21cm)