General description Includes 300 pieces of black and white nut covers in 6 sizes: M4*7, M5*8, M6*10, M8*13, M10*17, and M12*18. These hexagonal nut covers are designed to protect screws from rust, water, and dust, extending their service life while enhancing appearance. Technical specifications Sizes: M4*7, M5*8, M6*10, M8*13, M10*17, M12*18 Material: High-quality nylon Quantity: 300 pieces Usage Simply insert the screw of the appropriate size into the cover hole and press firmly to secure it in place. This process can be easily performed by one person. Other information Comes with a storage box that keeps different sizes and colors of hexagonal screw protectors organized and easy to carry.