Scratch Guard Self-Adhesive Clear Surface Protectors, 3/4 Dia. Circles, 20/Pack.Keep keyboards, desk accessories and other electronic equipment from sliding, while protecting the surfaces they're on with these self-adhesive circular protectors. Excellent for use on glass, metal, plastic, ceramic, wood or the back of picture frames. Diameter: 3/4 in, Thickness: N/A, Material(s): No-Slip, Color(s): Crystal Clear.