1. Parts that are tightly connected to mechanical equipment, etc. The gasket is used to increase the contact area, reduce the pressure, prevent loosening, and protect parts and screws. 2. Scope of application: automotive industry - cars, trucks, passenger cars, construction machinery, wind power equipment, agricultural machinery, foundry industry, drilling equipment, shipbuilding industry, mining equipment, utilities, rail transit. 3. Surface treatment: wash bright 4. Standard type: German standard 5. Product specifications: M4 x 6mm 10PCS M4 x 8mm 10PCS M4 x 10mm 10PCS M4 x 12mm 10PCS M4 x 16mm 10PCS M4 x 20mm 10PCS Hex nut 65PCS Washer 65PCS