1、5 Size Types: Knurled spring washer kit is available in 5 size types, namely M4 M5 M6 M8 M10, safe and practical. 2、304 Stainless Steel: Knurled spring washers are made of 304 stainless steel for high strength and resistance to high temperature, cold and high humidity. 3、Storage Box: All washers are packed in a strong and durable box, stored in specifications to prevent loss, and it is easy to find the right size washer. 4、Corrosion and Oxidation Resistant: Serrated conical spring washers are corrosion resistant, rust proof and oxidation resistant, which can be done for longer term use. 5、Wide Range of Uses: Knurled spring washers are widely used for interior decoration, outdoor construction, electrical maintenance and furniture repair. 20 x M4 Washer30 x M5 Washer40 x M6 Washer30 x M8 Washer20 x M10 Washer1 x Storage Box Item Type: Knurled Spring WasherMaterial: 304 Stainless Steel