Cat Trax has become the standard catamaran dolly for moving catamarans over sand, mud, rocks, or any surface. Lightweight and rustproof. Fast and simple tiedown attachment. Your cat rolls effortlessly on smooth running low friction Delrin bearings. Jumbo 11" x 21" balloon tires disperse weight, don’t dig in on soft surfaces. Tough padded end-caps hold the boat in line. No rust, no lubrication, no hassles. Stores easily on the tongue of your trailer. Cat trax to 8'6" beam, requires additional cradles. H20 add cradles #48010001, H21SC add cradles #1624.