【Excellent Material】 Our self-locking nuts are made of high quality stainless steel and nylon, which are corrosion resistant and can prevent loosening and twisting. Durable for long-term use. 【Nylon Insert】 Threaded hex nut to prevent loosening, the nylon insert prevents loosening and holds the nut in place when vibrated. These threaded inserts are waterproof, rust-proof and sturdy. 【Easy to Store】 Individual storage compartments are designed for easy storage. Thanks to The transparent box all around, the assortment of self-locking nuts is clearly visible inside, even when stacked. Very strong and will not open during delivery. 【Wide range of applications】 The stainless steel nuts can be used to drive bolts, threaded rods and Allen screws. Ideal for folding beds, wardrobes, miners, motors, textile machinery, workshops, motors, etc. 【What You Get】 You will receive 200 pieces / 7 sizes of the most commonly used self-locking nuts, including 5 M2 nuts, 50 M3 nuts, 45 M4 nuts, 40 M5 nuts,