Edwards Signaling 280A-PL Heat Detector AccessoryEdwards 280B series heat sensors come standard with a white plastic reversible mounting plate. The plate is designed for surface or flush mounting and installs directly to a standard North American 3 12 or 4 inch octagon box. Once the mounting plate is fixed, a simple twist will lock the sensor in place. It can be removed using a screwdriver to release the tamper resistant locking finger. This helps prevent unauthorized removal.