DW Drums 5000 Series Accelerator Single Bass Drum PedalAccelerator Cam (A Cam): Increases velocity and sensitivity by reducing the length of the stroke. Dual Chain Drive System: Provides smooth, powerful action with superior reliability. Tri Pivot Toe Clamp: Maintains secure, even contact with any bass drum hoop. Delta Ball Bearing Hinge: Offers ultra smooth, friction free pedal motion. Non Skid Rubber & Velcro Base: Prevents movement and ensures rock solid stability on any surface. Dual Bearing Spring