Aluminum alloy 20 x 1.75 BMX bike wheels from Wheel Master are beef-o-rama for any kind of riding you want to do. Single wall Weinmann 48 Hole ZAC30 rims with 14 gauge UCP spokes and 14mm axle dropouts. Flip Flop hub on the rear takes a standard 14T freewheel on one side, and a finer threaded 13T cog freewheel on the flip side. Accepts up to a 20 x 2.125 tire. ISO 406. Hand-built in the USA. Includes set of front and rear wheels. Silver color.