The Backing Plate Screw allows a rotary backing plate to fit on PC dual-action and random orbital buffers. This Backing Plate Screw adapter works with any Chemical Guys rotary backing plate. You can use the Backing Plate Screw adapter with the Meguiar's Dual Action Polisher G110, Porter Cable 7424 and the Ultimate Detailing Machine and DA machine. To ensure a good fit, always screw it in correctly and get it nice and tight. For safety and performance reasons, always tighten the backing plate screw adapter onto your polisher with a wrench.