Features:  Copper sump plug washers are suitable for all types of engine - including automotive and marine  Ideal for sump plugs, water, fuel and hydraulic accessories  Good electrical and thermal conductivity  Supplied in a handy plastic case  Specifications : Made from: Rust resistant copper 30 Pcs - 6 x 10 x 0.9mm 25 Pcs - 8 x 12 x 0.9mm 20 Pcs - 10 x 16 x 1.0mm 15 Pcs - 11 x 17 x 1.3mm 10 Pcs - 12 x 20 x 1.44mm 10 Pcs - 16 x 22 x 1.44mm