Build your own D-shaped steering wheel with the GT Pro Hub The GT Pro Hub is ideal for customising your own steering wheel. It is compatible with almost all steering wheels with a diameter of 320 to 350 mm and with a weight of only 1250 g, it has a pleasantly lightweight design. The hub is equipped with a total of 14 controls, of which 8 buttons can be individually adjusted. The patented HALL paddle modules provide an authentic racing feel.