It consists of two parts. One set consists of 304 stainless steel DIN934 locknuts (390) and the other of nylon with 304 stainless steel DIN985 hex nuts (130). The 304 stainless steel DIN934 nuts contain 7 sizes, including: M2 * 88pcs, M2.5 * 88pcs, M3 * 80pcs, M5 * 25pcs, M6 * 30pcs, M8 * 14pcs, to meet different requirements. The stainless steel DIN985 nylon + 304 nuts contain 7 sizes, including: M3 * 30pcs, M4 * 25pcs, M5 * 25pcs, M6 * 25pcs, M8 * 10pcs, M10 * 9pcs, M12 * 6pcs. The nylon insert engages in the thread to prevent loosening. The locknut is one of the important assembly parts of many Machines. It is an important component in the connection between washer and screw. It is used in very important areas of life. The combination of washers and locknuts perfectly solves most problems in life. The locknut is located in a storage box. In the storage box, you can easily find the desired nut model, and it won't get lost. You not only receive the best product, but also the best storage system for it.