Description:Made of rubber, dustproof and water resistant.Prevent dirt and build-up from forming on grease zerksUse to keep cap lost during service, and it must be used with standard grease zerks.Inner rib to keep cap securely fastened.Soft rubber for perfect fit.Specification:Material: RubberSize Chart:Size: Approx. 34x10x8mm/1.34x0.39x0.31inchPackage Includes:30 Pieces Brake Bleeder Screw Caps