The Inovonics door/window transmitter with wall tamper, reed switch, and EOL protection has a built-in magnetic reed switch on the side, with a magnet that supports a 15mm gap. A 2.2K ohm end of line resistor is included with the transmitter, and is required to operate it. The transmitter is fully supervised and includes a wall tamper switch that notifies the system when the transmitter is removed from its mounted surface.