The Thule 532 Ride On Adapter is a versatile, universal adaptor that enables almost all Thule roof mount bike carriers to be installed directly to all car factory rack cross bars. A cost effective alternative that eliminates the need to purchase a Thule multi-purpose base rack system that normally converts/replaces a factory rack. Includes one 32 inch load bar and tamper resistant universal mounting hardware for the front factory rack crossbar along with a universal clamp to attach the bike tray to the rear factory rack crossbar. Two bike maximum capacity.