MaxClamp technology provides 25% greater attachment force than the Aero Systems. FEATURES: Innovative foot assembles easily onto vehicles without pre-existing roof rack attachment points Integrated AcuTight Tensioning Tool indicates when the rack is safely and properly attached to vehicle Patented clamping technology securely holds the rack to the vehicle Quick assembly and install with click-in mounting brackets and no extra tools required Secures to roof with Thule One Key locks (sold separately) A kit-based roof rack system. Check the Thule Buyer's Guide to find out which roof rack fits your car SPECS: Cross Bar Compatibility: Aero Vehicle Mount Type: Naked Roof 4-Pack