The Trailer Valet 5X is a trailer dolly system with a built-in heavy-duty jack to make hitching and maneuvering your trailer much easier. The 5X has a towing capacity of 5,000 lbs. (tongue weight of 500 lbs.) and is rated on a flat, even surface. The Trailer Valet 5X hooks up to a standard trailer frame via a mounting bracket that allows users to swivel and stow the 5X when it's not in use. Then swivel it back down for use when you arrive at your destination. Simply use the jack function to raise the trailer so you can unhitch, then lower the Trailer Valet 5X to get your trailer level and into position.The Trailer Valet 5X is best used to move RV campers, cargo trailers, or boat trailers weighing up to 5,000 lbs. For added power, use the included Drill Attachment and your standard 20-24V Cordless Drill on the low gear, making it a motorized boat trailer or RV mover.The Trailer Valet 5X comes with never-flat solid rubber tires and an auto-brake function to keep your trailer in place. When the handle is down, the brake is engaged. To disengage, simply raise up the steering handle, and you're ready to move. Though the deep treads in the tire surface give you traction on different surfaces like gravel, dirt, or grass, you will get the best experience when using the 5X on well-packed surfaces or pavement. The 5X can push a trailer up a 5% (2.8 Degree) grade (will lower capacity); never pull your unit up any kind of incline.