Pedders Comfort Gas range features a unique VRD* valve which enables the average motorist to be within reach of a truly responsive shock absorber. The secret to Pedders VRD shock Absorber is within the shock 's valve, designed to control oil flow and respond instantaneously to different driving conditions. The result is the most responsive shock absorber available on the market today that provides the average motorist with an even greater level of driver comfort and vehicle performance.