The Yakima 4079 HullHound Hull Hound Roof Rack Kayak Saddles are sold in pairs and may be combined with another pair of HullHounds or a pair or Yakima Hully Rollers. . HullHound Saddles utilize a spring loaded base which automatically adjusts the saddles to the shape of your hull. Built in paddle tilt and wing shaped surfaces compensate for factory crossbar angles and a variety of kayak hull shapes and sizes. Saddles install without tools to all Yakima, Whispbar, Thule, Malone and Rhino Rack crossbars and most factory installed roof rack crossbars. Anti rotation adapters are included for Yakima Round Bar installations. Includes two saddles, one heavy duty tie down strap, 1 bowstern tie down strap and all installation hardware For additional security, the Yakima HullHound Saddles may be locked to your rack with 2 SKS Lock Cores sold separately.