1、SPECIFICATIONS: Including 215pcs hex lock nuts, with M3mm, M4mm, M5mm, M6mm, M8mm, M10mm, M12mm specifications, easy to use and replace. 2、MAIN PURPOSES: These hex lock nuts have good industrial strength, can replace lock washers, prevent bolt exposure, provide better safety and stability. 3、DURABLE MATERIALS: Made of premium stainless steel material for wear and corrosion resistance, with nylon inserts that are strong and crush resistant. 4、GOOD PERFORMANCE: With strong anti rotation ability to prevent the lock nut from weakening and loosening under vibration and torsion, thus reducing the clamping strength. 5、WIDE APPLICATION: Lock nuts ensure safe holding (reduces slippage) and long lasting hold of any item, commonly used in machinery, electronics and sports equipment etc.