The Symcom 460-120-MR has a line-line voltage range of 95-120V, the Macromatic PMD120 is 102-138V; the Symcom 460-120-MR has fixed undervoltage trip of 90%, the Macromatic PMD120 is adjustable from 80-95%; the Symcom 460-120-MR has adjustable unbalance of 2-8%, the Macromatic PMD120 is adjustable from 2-10%; the Symcom 460-120-MR has manual reset only while the Macromatic PMD120 offers both auto & manual reset; the Symcom 460-120-MR has SPDT contacts only while the Macromatic PMD120 has DPDT; the Symcom 460-120-MR can be both panel-mounted with two screws or mounted on 35mm DIN rail, the Macromatic PMD120 is for 35mm DIN-rail mounting (contact Macromatic for information on a panel-mount-only version in quantities).