Fits Quick release wheels out of the box and Thru-axle wheels with adapter accessory Fits all wheels from 20" up to 29" and tire size up to 3" Fits 9mm quick release bikes Fits 12-20mm thru axle bikes with adapter accessory (adapter sold as accessory) Holder arm can be separated from the base for convenient loading of front wheel off the car Holder arm with wheel installed easily docks to the base Locks the front wheel to the holder and the holder to the roof rack (locks included) Ability to fold flat when not in use Fits most roof racks up to 90mm by around-the-bar solution including Thule SquareBar roof rack with included adapter