This is the optional Disc Brake Conversion Set for the DuraTrax DXR500 Motorcycle. FEATURES: Adds disc brake stopping power to the front wheel of the DXR500 INCLUDES: Brake Disc, Micro Servo with Horns, two Steel Calipers with Mounting Hardware, Wire Harness and Instructions REQUIRES: Instaling on front wheel assembly following instruction sheet jxs 07/21/11 ir/jxs