Porter Cable 692900 Wrench This part is compatible with the following machines:7424SP Random Orbit Polisher, 97355 Type 1 5" Dust Collection Variable-Speed Random-Orbit Sander, 97355 Type 2 5" Dust Collection Variable-Speed Random-Orbit Sander, 97366 Type 1 6" Dust Collection Variable-Speed Random-Orbit Sander, 97366 Type 2 6" Dust Collection Variable-Speed Random-Orbit Sander, 7336 Type 1 Random Orbit Sander 6", 7336 Type 2 Random Orbit Sander 6", 7335 Type 1 Random Orbit Sander 5", 7335 Type 2 Random Orbit Sander 5" Also used with: 7424 Type 1 Random Orbit Polisher, 7424 Type 2 Random Orbit Polisher, 7334 Type 1 Random Orbit Sander, 7334 Type 2 Random Orbit Sander, 653 Type 2 3" Planer, 653 Type 3 3" Planer, 7346 Type 1 6" Sander, 7424XP Type 1 Random Orbit Polisher, 97455 5" Sander, 7345 5 Inch, 97466 (Type 1) 6" Sander This part is used to allow you to change the back up pad of your machine.