Traxxas XO-1 * TUNNELS EXTENSIONS REAR SKID DIFFERENTIAL CASE BULKHEAD BATTERY Left and Right Tunnels with Vent Cover (Part # 6420) Left and Right Tunnel Extensions (Part # 6419) Battery Tray Cups (Part # 6428) Two (2) Battery Hold Downs (Part # 6426) Two (2) Battery Hold Down Retainers (Part # 6427) Rear Diffuser (Part # 6436) Rear Differential Housing (Part # 6880) Includes: Tunnels Left/Right Vent Cover, 3x8mm (Part # 6420) Left/Right Tunnel Extensions (Part # 6419) 2 Battery Cups (Part # 6428) 2 Battery Hold-Downs (Part # 6426) 2 Battery Hold-Down Retainers (Part # 6427) Rear Diffuser (Part # 6436) Differential Housing (Part # 6880) Part number(s) included (in factory packaging): 6420 6419 6428 6426 6427 6436 6880