SFS series Single Speed Freewheel3/32" Chrome PlatedSuitable for BMX and Urban bikesFits 3/32" chains16-22 Teeth sizes.2 pawl mechanismBall bearingFits to ISO threaded hubs 1.375" x 24 TPINote: Always apply a little grease to the threads when fitting.Use TLSF2 Freewheel remover to extract. 2STTLSF2