Mirka Grip Backup Pad are available in over 25 sizes, shapes, hole configurations, grip types and densities. The Mirka 934GV Backup Pad is a multi-hole grip pad with 2.75" x 3.75" dimensions. Manufactured using advanced molded polymers and highest quality construction. Backup pads feature durable nylon J-hooks (unless otherwise noted) for use with grip style (Velcro-type) abrasives. Pads are perfectly balanced to eliminate vibration and provide superior finishing. Features and Benefits: Grip pads are available in over 25 sizes, shapes, hole configurations, grips and densities Manufactured using top quality molded polymer construction Balanced to eliminate vibration and provide superior finishing Medium density polyurethane foam is firm enough to level substrates while conforming to minor surface contours Pads feature durable nylon hooks for use with grip style abrasives