Xpert RC Gear Set with bearing

Xpert RC Gear Set with bearing. Replacement Xpert RC Gear Set Suitable for: SI-3601 SI-4501 SI-4431 SN-3501 SN-4401 SM-3501 SM-4401 SI-4401-HV SI-4501-HV SN-4501-HV SN-5401-HV SM-4501-HV SM-5401-HV