This is a Curt 1 7/8" chrome ball with a 1" diameter by 2 1/8" long shank. The ball capacity is rated at 3500 lbs. The 1 7/8" Refers to the Size coupler that will attach to it. This trailer ball size is very common on smaller utility trailers, jet ski trailers, and small boat trailers. The 1 inch Shank refers to the size whole your trucks ball mount will be using.