Pre-lubricated assembly consisting of 39” long S-93 inner shaft and 36-1/4” long S-77 outer sheath is ready to install on your motor. Be sure to unplug your motor before doing any maintenance and never operate your Foredom without the outer sheath attached. We suggest that you view our video before installing this item. This shaft and sheath combination comes equipped on ALL Motors listed below: M.SR, M.SRM, M.SRB M.TX, M.TXM, M.TXB M.LX, M.LXM, M.LXB Also use to replace broken or worn shafts on these older, discontinued motors: M.SR, M.SRM, M.SRB-1/8HP models sold prior to Nov. 2005 M.L, M.LM, M.LB M.PG M.S, M.SM, M.SB M.CC, M.MM, M.DD M.R, M.RB, M.K M.500 M.900 and M.990