It Consists of Two Parts. One Made of 304 Stainless Steel Din934 Locknuts(390 and The Other Made of Nylon With 304 Stainless Steel Din985 Hex Nuts(130). The 304 Stainless Steel Din934 Nuts Include 7 Sizes. Including: M2*88Pcs. M2.5*88Pcs. M3*80Pcs. M5*25Pcs. M6*30Pcs. M8*14Pcs. To Meet Different Requirements. The Stainless Steel Din985 Nuts Nylon + 304 Includes 7 Sizes. Including: M3*30Pcs. M4*25Pcs. M5*25Pcs. M6*25Pcs. M8*10Pcs. M10*9Pcs. M12*6Pcs.The Nylon Insert Engages A Thread. To Prevent Loosening. The Lock Nut Is One of The Important Assembly Parts of Many Machines. It Is An Important Part of The Connection Between The Washer and The Screw.Used In Very Important Areas of Life. The Combination of Washers and Lock Nuts Perfectly Solves Most of Life'S Problems The Lock Nut Is In A Storage Box. You Can Easily Find The Mother Model You Want In The Storage Box and It Will Not Be Lost. Not Only Will You Get The Best Product. But Also The Best Storage System for Them