Dual Action Pads super Polyurethane Hook, Loop velcro replacement backing pads for Random Orbital sanders. Standard profile Velcro with side dust extraction vents which can remove more unwanted particles from the sanding area. Featuring dust extraction channels from the outside & cooling from the centre hole. Excellent resistance to tearing & other damages & has long lasting foam. Abrasive Diameter: 150 mm. Surface diameter: 148 mm. Holes: No Holes. Thread 5/16 UNF. Foam Layer 12 mm. Density: Medium. Max PRM 10, 000.