Union Pads and Abrasives OEM7 can be used with standard sandpaper sheets or adhesive-back sheets and rolls. It has eight holes for dust collection. The easy installation involves removing the mounting screws to replace the pad. This part is compatible with - Porter Cable: 340 Palm Grip Finishing Sander, 340 Type 1 1/4 Sheet Sander, J-340 Type 1 1/4 Sheet Finishing Sander, 340B Type 1 Sander