The loop powered door magnet is the latest innovation from Zeta Alarm Systems. The ZTA-DH is an addressable loop powered & loop controlled door holder. It takes all it’s power from the loop, so there is no need for a separate power supply or battery

ZIOU-DG – Zeta Addressable Input/Output Unit with Isolator provides two voltage-free, single pole, change-over relay outputs, a single monitored switch input and an unmonitored, non-polarised opto-coupled input.