This UPS features includes Voltage Regulation (keeping voltage within nominal operating ranges) prevents equipment lock-ups due to power sags and keeps equipment from heating up (power supplies require more current when voltage is low). Plays well with others....as an add-on to every sale. Plug the M1500-UPS into the Always On outlet of any Panamax component to combine the award winning features of the component product with the enhanced features of the M1500-UPS. Total system capacity would be 15 amps. Use with a M4310 and occupy only three rack spaces for less cost than the competition. Or use with a M5300 with more features for the combined cost of the competition.