The Thule Xadapter1 is an adapter kit that makes it possible to connect the Thule 589 Velo Vise bike rack and Thule 590 V2 bike racks to the Thule Xsporter, Thule Rapid Aero, and Thule Professional rack systems.FEATURES – Easy to follow instructions- Mounts Thule 589 Velo-Vise and Thule 590 V2 to Thule Xsporter Truck – Racks, Thule AeroBlades, and Thule Professional Racks- Enough hardware to mount one carrier