You can choose a Single ULTRA Connection Set (UCS) or upgrade it to a Dual UCS which will save you a lot of time when swapping mini and regular/large size bikes as you don’t have to unbolt or detach the cones with thrust bearings and screw them into other holes. This set can also be as a spare in case of any damages during unforeseen incidents.
Fits Wheelie Machines: V4.0 / V4.0 PRO / V4.0 MINI (30mm versions only) / Gen 5 / 5 MINI / 5 PRO / 5PRO Max / ULTRA