Description: Brand new. 10mm screw suitable for installing items with a thickness of 0.1-7mm. 16mm screw suitable for installing items with a thickness of 0.1-13mm. 23mm screw suitable for installing items with a thickness of 0.1-20mm. Can be used on a variety of smooth hard surfaces including glass, wood, ceramic tile, metal, gypsum, etc, Please Note that Not Suitable For drywall, wallpaper, painted walls, and rough surfaces, once you stick on this surface, it can not be removed, or your wall might be damaged. The back adhesive is a self adhesive tape on the back, which can be used after tearing off the protective film. .