The DEWALT DW4945 is a 4-1/2-inch steel-reinforced rubber backing pad designed for use with 4-1/2-inch grinders. It features a 5/8″-11 locking nut, ensuring a secure attachment to the grinder. This backing pad is ideal for attaching sanding discs, foam bonnets, and polishing bonnets, providing durability and resilience for various sanding applications. It operates at a maximum rotational speed of 12,000 RPM.