This is a set of 4 wheels. The wheels are CNC cut from 1" thick Rubber and sandwiched between 1/2" UHMW that are chamfered. Each wheel has two sealed ball bearings in them. Each wheel has a #35 30 tooth chain aluminum chain sprocket mounted to it. The wheel shafts are 3/4" 6061 Aluminum steped down to 5/8" for the included sealed ball bearings, then steped down again to 1/2" with a flat spot milled onto it for fastening to the tensioners. The wheels come unassembled, you need to bolt them together per the HD2 manual. The wheels weigh 4.4lbs.
To purchase both the track and wheels see HD2 Pair of Molded SplicXeless Tracks and Wheel Set - Generation 4 (TD-123-002)