Dim., 1.862 in. O/a dia, 0.433 in. Thk excl dial shafts, main dial shaft protrudes 0.958 in. Nom, sub @dial shaft protrudes @0.904 in. Nom, both shafts 0.0733 in. Diameter w/two slits 90 degrees apart on protruding end, slits 0.010 @in. W, 0.187 in. Dp, top and bottom have two 0.200 in. Unthd mtg holes and three holes tapped no. 1-72 unf-2b, bottom has 0.500 in. Diameter hole for mtg motor, top has two 0.073 in. Diameter holes for dial shafts, gear ratio-motor to main dial shaft-464.46 to 1, ratio-sub dial shaft to 270 degrees rotation of main dial shaft-12 to 1, backlash at center shaft w/motor locked-1 degrees max, total travel of main dial shaft-280 deg, gear train starts operating through entire range w/1.8 volts max applied to motor, counter clockwise rotation of motor produces clockwise rotation of both shafts