【Outstanding Material】Our metal washers are made of high quality copper, which has good electrical conductivity, thermal conductivity, 1083℃ melting point and durable for daily use and can be used repeatedly.< /p> 【Easy to use】O-rings are very easy to install, copper flat washer surface is smooth, reduce friction between fasteners, prevent leaks, insulate, prevent loosening or leaking pressure. 【Easy to store】These copper flat washers are designed with a storage box, which makes the sealing ring gaskets safer and more convenient to store, easy to carry and store. maintain a good classification. This design will improve work efficiency. 【Wide Application】O-rings are perfect for water, sump plugs, fuel and plumbing fittings. The water seal kit is perfect for electrical connections on household appliances, appliances, automotive and marine. Ring washers are really cool tools. 【What you will get】 Flat washers include 30pcs M5*9*1, 30pcs M6*10*1, 20pcs M6*12*1, 20pcs M8*12*1, 20pcs