Feature: 1. Made of pure copper, it is not easy to rust in humid environment, is corrosion-resistant, and has strong anti-oxidation ability. Specification: Item Type: Flat Knurled Thumb Screw Material: Pure Copper Head Diameter: Approx. 11mm / 0.4in Head Thickness: Approx. 8mm / 0.3in Package List: 50 x Screws |