The Dt swiss Ring But Tool for Ratchet Drive Rear Hubonly works on ratchet drive hubs such as the 240s and 350 as well as those found on higher end complete wheels Dt swiss Ring But Tool for Ratchet Drive Rear Hub Features Ring nut tool required for removing and replacing inner bearings on ratchet drive rear hubs, which are located behind the internal ring nut only works on ratchet drive hubs such as the 240s and 350 as well as those found on higher end complete wheels, for pawl drive hubs please use tool hbdt5266 simple to use, and fits into a vice for workshop use, do not over tighten the vice in use as this can crush the tool