This channel socket has been designed specifically to fit through the openings of 41mm channel to allow M10 bolts or nuts to be tightened. Ideal for use when fastening channel to walls or ceilings etc. This channel socket can be used alongside unistrut type channel with m10 nuts. 17mm hex for M10 setscrews and nuts. Assembled using a 1/2″ square drive ratchet or impact wrench.