These carriers are delivered ready to use; no assembly work is required. The assembly is simply a matter of turning a hand wheel, which is a really quick, easy, and ergonomically satisfying task. By turning the key in the tension wheel, the carrier is locked onto the tow ball. Another nut is tightened with an integrated handle, and then the carrier is held securely in place. The Buffalo is TÜV-tested for 4 bicycles according to the proposed ISO standard R18-904-4, a standard that is significantly stricter than current requirements. The tilting mechanism is safer than most hanging carriers, as the weight of the bicycles can be absorbed when pressing down the foot pedal, and there is a double tilt stop - a steel loop as well as the reinforced plastic foot pedal. When you lift the bicycles back to the vertical position, the foot pedal snaps back into its closed position and holds the weight of the bicycles. Before tilting, a safety screw must be removed with a hand-turn knob and reattached when the carrier is back in the vertical position. When attaching the bicycles, actually two people are required - one to apply gentle pressure on the bicycle load so that the securing pin is not stressed, and then it can be easily turned.