Using the Thule EasyFold 931 2 Bike Carrier is easy. First, make sure your towball is compatible with the carrier. Attach the carrier to the towball and secure it. Then, place your bikes on the carrier and use the detachable frame holders with the Thule AcuTight torque limiter knobs. Tighten the knobs until you hear a click, which means you've reached the optimal torque. You can lock the carrier to the tow bar and each bike position to the carrier for added security. When you're done, fold the carrier up for easy storage. Note that this carrier isn't compatible with 47mm gooseneck / Euro style and interchangeable ball mounts with cone - shaped bases. To maintain it, keep it clean and check the connections regularly for any signs of wear and tear. If you notice any issues, have it inspected by a professional.