Hekatron Electromagnetic Door Retainers are used to keep self-closing doorways such as fire doors, smoke doors and other doors or gates open. They must be linked to a Smoke Detection System, which, if a fire occurs, breaks the circuit to deenergize the electromagnet and allow the door to close, thus stopping the fire and smoke from spreading.
For wall mounting
No remanence
Integral spark-supression diode
Polarity reversal protection.
The Hekatron THM-312 Electromagnetic Door Retainer "Standard".