1. Made of 304 stainless steel, rust-resistant and corrosion-resistant, durable, not easy to break, and can be used for a long time in humid and various corrosive harsh environments. 2. Cotter pin with hairpin design for fast and safe fastening of bolts and pins. 3. Flat and sturdy: the surface is flat and smooth without burrs, with high-quality workmanship and durable stainless steel material. 4. Scope of application: suitable for repairing and fixing of automobiles, machinery, garages, workshops, power equipment, cars, trucks, lawn mowers, small engines, etc. 5. Installation location: After tightening the nut, insert the cotter pin into the nut slot and bolt tail hole. 6. Material: 304 stainless steel 7. Specifications: M1.5 x 25 (d: 1.5mm, L: 25mm) M2.5 x 25 (d: 2.5mm, L: 25mm) M2.5 x 40 (d: 2.5mm, L: 40mm) M3 x 30 (d: 3mm, L: 30mm) M3 x 40 (d: 3mm, L: 40mm) M4 x 60 (d: 4mm, L: 60mm) 8. Product composition: M1.5 x 25 x 30 PCS M2.5 x 25 x 25 PCS M2.5 x 40 x 25 PCS M3 x 30 x 25 PCS M3 x 40 x 25 PCS M4 x 60 x 20 PCS