The 6" Spun Aluminum nose wheel with 5/8 bearings. Comes centered when using the MX o-ring standard wheel hub but can also be purchased with the MX offset hub (no o-ring with offset hub. Requires the use of a tube. The bearings are centered and rim halves are mounted from one side, creating a narrower wheel than the std. MX hub).Nose wheels comes complete with nuts, bolts, washers, valve stem, o-rings if required and the MX hub. Can be ran with or without tube. May also be used as main wheels. Wheel width options 3.5" (1.75" rim & 1.75" rim), 4" (2"rim & 2"rim), 5" (2.5"rim & 2.5"rim), and 6" (2.5" rim & 3.5 rim when used as wide main wheel). HEGAR MANUFACTURING 503-659-1234