A jockey wheel for vehicular use is a retractable adjustable-height wheel used on the front of trailers (or caravans) with either a single axle (two running wheels) or more close-coupled axles at or near the centre of gravity whereby without additional support, the trailer would not remain level. The jockey wheel is situated close to the towing hitch and has a built-in screw jack to enable the trailer nose to be lifted over the tow ball of a car or other powered vehicle. The screw jack can then be used to lower the trailer nose onto the tow ball. Once securely attached to the towing vehicle, the jockey wheel's jacking action is fully retracted for stowage. The jockey wheel can also be unclamped and lifted as far as possible to give the greatest ground clearance before reclamping prior to a journey being made.

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