Clarke RP115C Rubber Backing Pad With Velcro Hole has a size of 4.5 inches and is usually used in conjunction with Velcro sanding discs or polishing pads on power tools such as angle grinders or orbital sanders. This type of support plate provides a secure hold for sanding or polishing discs and allows easy attachment and removal thanks to the Velcro system. These backing pads are commonly used in various applications including woodworking and metalworking, bodybuilding, and general surface preparation work.