"Move a loaded trailer around with ease using the Tow Tuff Hard Surface Trailer Dolly. Perfect for heavy trailers up to 1,000 pounds, this powder-coated steel trailer dolly comes with three 5"" polyurethane casters that work well on cement and tar surfaces. The ball height is adjustable from 21-1/8"" to 25-3/8"", and it can be set backwards or forwards for better load distribution. The trailer ball is 2""."