This Genuine Casio G-Shock Black Resin 21.5/16mm watch band features a silver tone stainless steel buckle, a matte finish, and water resistance. The Casio strap is created from a durable and thick resin contruction. The strap measures 21.5mm that integrates to the caseback at 16mm. Regular Length. Fits: GS-1010-1A, GS-1100, GS-1001.