Size: Outer diameter: 12mm - Inner diameter: 4.2mm - Thickness: 2.8mm Material: 304 stainless steel is an austenitic stainless steel, austenite is partially transformed into martensite (magnetic) when working atcold process, so it will be non-magnetic or weakly magnetic Function composite screw washer is suitable for outdoor or humid environment, no rust, corrosion resistance, acid resistance, better water resistance and applicability, and not easy to break [Advantage] - One-piece fender joint is slightly angled but flattens when tightened.Glued gasket provides an airtight seal between the bolt or screw and the hard surface [Application] - It can prevent thermal expansion and cold contraction during installation, improve the fixing effect, sealing, dustproof and waterproof functions. Also acts as a cushion to protect against vibrations Color: Silver Quantity: 200 pieces