These are new carbon reinforced hub carriers that have been specifically designed to accommodate double-cardan swing shafts. They have a built in caster of 4 degrees and are compatible with Tamiya&rsquos short reversible suspension arm systems seen on the TB-03, TB-04, TA-05, TA-06, FF-03, TRF 416, and 417. - Carbon Reinforced Hub Carrier (4deg) x1 - The design prevents it coming into contact with double cardan shafts when used. - Can be attached directly to Item 53928 Short Reversible Suspension Arm set. - 4deg angle makes the car well-suited to smaller circuits with lower-speed corners. - Compatible with cars fitted with Item 53928 Short Reversible Suspension Arms.