Description: These flat washers made of copper, which provides more tighter seal and higher heat resistance. Flat washers are mainly used to reduce pressure and friction, prevent leakage, isolate, loosening or disperse pressure. All of these items are packed in a sturdy case, easy for your storage and use! Widely meet your various home DIY demands and suitable all types of engines be it, marine, generators, machinery and plant use. 200Pcs Flat Rings copper seal washer gasket assortment, contains 9 sizes: 30 pieces M5*9*1mm, 30 pieces M6*10*1mm, 20 pieces M6*12*1mm, 20 pieces M8*12*1mm, 20 pieces M10*14*1mm, 20 pieces M8*14*1mm, 20 pieces *16*1mm, 20 pieces *18*1.5mm, 20 pieces M14*18*1mm. Specification: Material: Copper Size Chart: Storage Case Size: approx. 13cmx6.5cmx2.3cm/5.12inchx2.56inchx0.91inch Package Includes: 30 Pieces M5*9*1mm 30 Pieces M6*10*1mm 20 Pieces M6*12*1mm 20 Pieces M8*12*1mm 20 Pieces M10*14*1mm 20 Pieces M8*14*1mm 20 Pieces *16*1mm 20 Pieces *18*1.5mm 20 Pieces M14*18*1mm 1 Piece Storage Case Note: Please allow slight dimension difference due to different manual measurement.