Features: new and high quality Selected from 65 steel material, the black coated can prevent oxidation, corrosion resistance, easy installation. 340pcs in 7 size. We have the 7 most commonly used size: M3x9 (60pcs), M4x12 (60pcs), M5x12 (60pcs), M6x14 (50pcs), M8x18 (50pcs), M10x20 (40pcs), (20pcs), a variety of size can meet your requirements of different size. Locking rings can be used for quick fixings and repairs. The locking Rings exerts a spring force between the head of the fastener and the base material and ensures that the screw thread fit tightly to thread of the nut and base material Mainly used in electrical appliances, lawn mowers, engines, automobiles, trucks, trailers, electronic devices, caravans, boats, furniture, industrial production, etc. All locking rings is store in plastic box, which isvery easy to store and find. Each size is store separately in the storage box, which is easy to find as well as efficient to use and install. Specifications: Material:Steel Package Includes: 60Pcs M3x9 Washers 60Pcs M4x12 Washers 60Pcs M5x12 Washers 50Pcs M6x14 Washers 50Pcs M8x18 Washers 50Pcs M10x20 Washers 20Pcs Washers note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.