The Yakima Ridgeline Tower 4PK is a revolutionary tower to attach a base rack system to modern vehicles with factory flush side rails.Unique, adaptive inner and outer clip design for secure, accurate rail contactTower material is made of stainless steel, glass reinforced plastic and elastomer paddingBarBed with 12 degrees of pitch adjustment levels front and rear crossbars on a vehicle with curved flush railsThe tower's adaptable BarBed material conforms to work with RoundBar, CoreBar and JetStream barsRisk-free torque set installation, tool includedMaximum load rating of 220lbs(100kg), depending on vehicle and bar ratingLockable to vehicle (SKS locks sold separately)Clips sold separately