The Flex Pro Professional Backing Plate with Drill and Dual-Action Adapters is a unique and versatile backing plate with interchangeable adapters; one makes the plate a drill chuck backing plate and the other makes it a pneumatic backing plate. Flexible Backing Plates minimize heat transfer, while it flexes just enough to contour to your vehicle's bends and curves. The Flex Pro 3 inch backing plate comes with both drill attachments (1/4 inch shank fits most drills) that enables you to use it with any drill of your choice and Porter Cable or DA adapter (standard 5/16 inch). The Flex Pro backing plate is smaller than the pads to allow a generous lip of foam to protect the paint surface. Even if you turn the pad onto its side accidentally, there is an inch of soft, beveled urethane between the edge of the plate and the inner construction. Chemical Guys Flex Pro Backing Plate provides the safest, most durable surface for your pads so that you get the best performance possible from your pads..