Compatible screw diameters: M16, M18, W5/8"; Usable range length: 1.6 inches (40/58 mm); Size: Diameter 1.8 x 2.4 inches (47 x 60 mm); Material: Body: Hard PVC, Inner cap: Polyethylene; Anchor bolt cosmetic, rust resistant, protection, safety measures; One-touch mounting; Quantity: 2 pieces