The 6" x 4" (2" rim x 2" rim) Spun Aluminum nose wheel with 5/8 bearings, 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.