Token's 1/2 x 1/8'' Chromo Single Speed Freewheel is a finest top quality single speed freewheel. The sprocket body & covers are machined from Cromo CNC & the teeth are designed for 1/2 x 1/8'' chains. The internals consist of 2 sealed bearings & it is available in 16, 17, 18 or 20t.