DW Hardware DWCP5002AD4XF 5000 Series AD4 Extended Footboard Bass Drum PedalThe Accelerator Double Pedal Goes Long An elongated footboard design adds increased power and agility to time honored Accelerator performance in the DW 5002 AD4XF ("Extended Footboard"). Now you can access full length windups and easier heel toe doubles with the same AD4 response and durability you trust. The AD4XF's Accelerator Drive system creates an indirect relationship between the sprocket and footboard for maximum velocity and sensitivity.