High quality internal tooth washer kit. Made of high quality 65 manganese steel pushing on quick lock washers snap fasteners, anti-corrosion and durable. 7 size from M3 M4 M5 M6 M8 M10 M12 in a transparent box, applicable different sizes of fasteners. Widely used in machinery equipment, industrial production for shock absorption and insulation. A lock washer exerts a spring force between the head of the fasteners and the substrate to create more friction and resistance to rotation. Package includes: 280pcs Washer. 1 x clear plastic case. M3*60pcs, M4*60pcs, M5*60pcs, M6*50pcs, M8*50pcs, M10*40pcs,M12*20pcs See more details. Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.Note: The data is all manually measured, please allow 1-3cm error, due to the light and display difference, there will be some color difference, the actual object received shall prevail.