The YAMAHA FP9C Single Bass Drum Pedal Chain Drive with Case features an auto-lock spring adjustment for quick and easy operation.Quick-Adjusting Cam/Link The chain drive gains tension gradually throughout the stroke as the pedal is depressed. Switching the cam from C1 to C3 reduces the initial tension. The direct-drive gains tension after the tension from the first step recedes. After initially dropping, the tension from the direct-drive increases steadily throughout the stroke. Switching the cam from D1 to D3 increases the initial tension.Double Chain DriveThis durable, reliable double chain drive boasts fluid movement. The cam at the bottom of the chain can be moved into three positions, allowing the drummer to fine-tune the pedal's action to match their preferred performance. It can also be used as a belt drive by replacing the belt that is included with the pedal.Axle-Stabilizing Bearing ChamberThe frame and bearing cover (blue parts) are independently smoothed and precisely fabricated before assembly, allowing them to be aligned with the central axis of the shaft and ball bearings to unleash a smooth rotation.Low-Profile Stabilizing HingeThe hinge base and cover (blue parts) are independently smoothed and precisely fabricated before assembly, allowing smooth footboard performance.Easy-Access Auto-Lock Spring AdjustmentMoving the spring adjustment knob upward greatly simplifies the traditionally troublesome tension adjustment process. The knob is locked at a 90-degree angle which prevents it from coming loose on its own.Weight-Adjustable BeaterAttaching weights to the beater allows drummers to attain their preferred sound and feel. Aluminum (3g) and brass (9g) weights are both available and can be attached and removed easily.Independent Beater/Footboard Angle AdjustmentThe beater angle and footboard angle can be independently and freely adjusted. The inclusion of an angle checker allows drummers to easily re-create their preferred settings.Ball Bearing Drive ConnectionThe tip of the footboard comes equipped with ball bearings, allowing even smoother performance.Anti-Skid Heel SpikesThe heel of the pedal comes equipped with spikes that prevent slipping when playing and provide improved stability.All-Bearing Universal JointNewly-designed universal joints add ball bearings to all axes. The seamlessly smooth rotation dramatically improves the action and operability of the secondary pedal.