Redcat Racing Aluminum Steering Knuckle Set Steering knuckle set, aluminum. (New 4mm Style) Genuine Redcat Racing Spare Parts Redcat Racing Part Number MPO-03 For troubleshooting and warranty information please contact a Redcat Racing Customer Service Specialist at 602-454-6445 or by emailing amazonsupport@redcatracing.com NOTE: Please read the User Manual before use.