High Quality: All products are made of tough nylon, heavy duty heavy duty nylon. corrosion and & agrave; wear. With washers to increase contact area, reduce pressure and protect parts and screws. Perfect for electrical connections to medical devices. Commercial and automotive, automotive and marine applications. Pre-classified for quick identification and protection against loss. Very convenient to use. to use. Easy & agrave; install and durable & agrave; use, 8 popular sizes including the most common and common sizes -M2 M2.5 M3 M4 M5 M6 M8 M10, different sizes, for whatever you need.