Discover the robust Norton Rixson 993M Electromagnetic Door Holder, perfect for ensuring your doors stay securely open. This device boasts a powerful 300 lbs holding force and comes with a switch box for easy installation. Its total projection is 5-1/4 inches, and it features an armature plate that is thru-bolted for consistent contact. The special heavy-duty armature includes an adjusting screw for precise alignment. Additionally, it has a test switch for functionality checks and can be ordered without a switch for frequent use. Remember, substantial wall reinforcement is needed for installation. Upgrade your door's functionality with this reliable and durable door holder!