Northern Industrial Adjustable Trailer Dolly - 600-Lb. Capacity Ball height adjusts from 12 1/2in. to 21 5/8in. Allows easy maneuverability of utility, boat, cargo, personal watercraft and other small trailers Fits 1 7/8in. and 2in. couplers Includes 1 7/8in. hitch ball Powder-coat finish