MAXVIEW 1 x Boxed Jockey Wheel Clamp. The Jockey Wheel Clamp offers a quick, reliable and temporary mount for a TV aerial mast onto a caravan jockey wheel. Sliding Clamps offer adjustment in mast position, moving mast away from A-frame obstructions. Universal fitment for any mobile TV aerial mast up to 2 inches (50.8mm). Easy assembly with wing nuts, without the use of tools. High quality, durable and robust construction.