Single Speed FreewheelSuitable for BMX and Urban bikesChrome plated steelFits 1/8" chains16, 17 or 18T2 pawl mechanismBall bearingFits to ISO threaded hubs 1.375" x 24 TPINote: Always apply a little grease to the threads when fitting.Use EZ-off 4-Dog type extractor tool to remove - such as Cyclo item 2CY06397