The CMO unit is 11 pin DPDT while the Macromatic COKP is SPDT 8 pin–the socket must be changed and some rewiring done; the CMO unit has a drop-out voltage setting fixed at 95% of the pick-up setting while the Macromatic COKP has adjustable drop-out setting of 50-95% of the pick-up setting; the CMO unit has a range of 0.05-0.25A and the Macromatic COKP has a range of 0.1-1A–if the monitored current is above 0.1A, consider the COKP05A62 unit which has a range of 0.5-5A