The kit comes with a RIT Centering tool. It looks very similar to an allen key <g>. Center the rit (by ear), loosen the set-screw, align the index hash at 12 O'clock, and tighten the set-screw. Dan / WG4S / K2 #2456 <snip> I want to calibrate my rit/xit on center again. </snip>