The Allen QR hitch rack is the perfect way to get out there and bring your bikes with you. - Locking hitch insert fits either 1 1/4" or 2" receiver hitches (2 and 3 bike models) or 2" receiver hitches (4 and 5 bike models). - Patented, quick install hitch secures and tightens rack inside of receiver hitch; includes two keys. - Arms fold out of the way when not in use and rack tilts back when needed. - Patented individual tie-down cradles secure and protect your bicycles. - Accommodates a wide range of bicycle frame designs - Minor assembly required. No tools needed to install rack to the vehicle. - Important installation note: never use on trailers. Will not work with Class I receiver hitches.