Coupling kit with six different couplings for use on freewheels. 1> TT motor plastic shaft2> N20 motor (Φ3, D-axis)3> SG90 and MG90S servo4> 25T steering gear (standard 945, 945, 996, S3003 series)5> 25 motors, etc. (hexagonal copper couplings Φ3, Φ4, Φ5 D-shaped motor shaft)6> LEGO cross shaft