Size and Color: M10 Nut and Bolt Caps, Key Size 17. Color: Black, Number of Pieces per Pack: 100 Pieces. MATERIALS AND QUALITY: All our hole plugs are made of high quality plastic that is resistant to deformation, UV rays and all weather conditions. PERFECT DESIGN: Designed with extreme attention to detail, the nut covers feature a thick core and a unique design with snap-on tabs to permanently cover the hex nut bolts. It forms a harmonious whole, thus giving the final product an aesthetic appearance. SAFE: The nut covers and screw covers protect the hex screws and protruding nuts from the elements and largely prevent corrosion and rust. The hexagonal cap shape also prevents injuries. Installation and use: Assembly is extremely simple thanks to the hexagonal tabs. Nut covers are used in the general construction sector, for the construction of machines and equipment, furniture, playground equipment and other garden architecture elements, where aesthetics and quality are of paramount