Truths Entrygad Dual arm operator number on the arm reads 40754 center mounting hole center of mounting plate to the end of straight arm measures 10 1/2″ small arm end with clip measures 4 7/16″ from center hole in mounting plate to end of arm common replacement crank numbers are 20810, 20544, 40372, 40471, 40254, 40753, 30470, 30472, 40754, L30841, 31358A, 31358, 30637, 30842 these are common but not always please verify the dimensions on yours before ordering.