The 3M 50392 Hookit Back Up Pad is a genuine 3M accessory designed for 150mm dual-action and random orbital sanders. Featuring a 15-hole spiral pattern and direct flow channeling, it ensures maximum dust extraction and prolongs abrasive life. Constructed with high-density foam, a rigid center, and a soft edge, this standard firmness pad offers enhanced flexibility. It has a 5/16-24 EXT thread size, a 19mm center hole diameter, and supports up to 12,000 RPM.