Made of high quality polyurethane which is durable, lightweight, flexible, heat-resistant and well-balanced. Fits most dual-action polisher with a 5/16"-24 M8 thread. Hook and loop backing pads, Diamater: 5", Screw Thread: 5/16"-24 (M8), Maximum Operating Speed: 12000 RPM, Type: Non-vacuum style. Reinforced Inner construction utilizes steel struts molded into the center hub to withstand high frequency to keep the plate stability while achieving a consistent, smooth finish. Dual-Action flexible hook and loop backing plate make disc change easy and fast, work with most pad materials with hook-and-loop backing system like foam, wool, paper, microfiber and more. Ideal for spot sanding focus areas, removing solder joints and rust spots on metal products, deburring furniture and woodwork, mold manufacturing, polishing automotive and detailing work, etc. Specification: Material: Polyurethane, Steel Diameter: 5-Inch (125mm) Size: 5/16 inch-24 Threads (M8) Maximum RPM: 12,000 Density: Medium Attachment System: Hook and Loop Thickness: 3/8 (10 mm) Package Included: 2 x Hook and Loop Backing Pads