Forget throwing your back out lifting kayaks on and off your roof rack. Instead attach the Thule Hullavator Pro Kayak Carrier onto your Thule Crossbars and let the Hullavator Pro do the heavy lifting for you. This carrier uses gas-assisted struts to lift and lower 40-pounds of the kayak's weight alleviating up to 90% of the heavy lifting required to load and unload your kayak. How exactly does this ingenious system work' Well Thule designed the Hullavator Pro with double-extending arms that lower the kayak up to 40-inches for faster loading and unloading. That means you can simply lower the each arm to your vehicle's side secure your kayak and use the assisted lifting mechanism to easily place the kayak onto your roof. The gas-assisted struts also work in reverse keeping you from painstakingly lowering heavy kayaks off your roof rack. This one-boat carrier fits most kayaks with its expanding corrosion-resistant cradles. Eight padded attachment points provide a secure fit without scratching or damaging your favorite kayak. Included with this carrier are all necessary straps for carrying and attaching one kayak. Note that the Hullavator Pro conveniently attaches to all Thule Crossbars except for the Aeroblade Edge and it's compatible with Thule's One Key System for convenient one-key locking with Thule racks and carriers.