PU Material: This sanding pad is made of high quality PU material, which is durable. The sanding pad of this material can ensure excellent sand disc smoothness and polishing effect, so as to achieve the effect of not injure the user. Easy to Use: This 8-hole grinding wheel features 3 built-in mounting screw holes and a shackle design, it makes setup quicker and easier, and allows for quick sandpaper changes. Special Design: This wheel is designed with 8 holes to work with sanders with dust collection system. This dust collecting function of this thumb rest is super convenient, the 8 dust holes attract dust effectively and debris in the dust bag assembly. Size of this sanding pad: Our sanding pad is 125mm in diameter and has 8 dust holes and 3 screw holes. Before purchasing, please make sure our sanding pad fits your sander.