The Symcom 460-575-MR has a line-line voltage range of 475-600V, the Macromatic PMD575 is 480-600V; the Symcom 460-575-MR has fixed undervoltage trip of 90%, the Macromatic PMD575 is adjustable from 80-95%; the Symcom 460-575-MR has adjustable unbalance of 2-8%, the Macromatic PMD575 is adjustable from 2-10%; the Symcom 460-575-MR has manual reset only while the Macromatic PMD575 offers both auto & manual reset; the Symcom 460-575-MR has SPDT contacts only while the Macromatic PMD575 has DPDT; the Symcom 460-575-MR can be both panel-mounted with two screws or mounted on 35mm DIN rail, the Macromatic PMD575 is for 35mm DIN-rail mounting (contact Macromatic for information on a panel-mount-only version in quantities).