- Operates over distances between 30 ft (9 m) and 350 ft (107 m) - Six levels of switch-selectable sensitivity - Built-in alignment sights and tamper protection - Automatic range adjustment, signal synchronization, and contamination adjustment - Remote indicator plate annunciates detector status and provides test points for voltage monitoring The D297 12 V Projected Beam Smoke Detector is used in clear open structures such as arenas, atriums, auditoriums, ballrooms, churches, factories, museums, and warehouses. Each detector consists of a transmitter, a receiver, and a remote indicator plate. Because the transmitter and receiver typically mount on the ceiling or high on walls or columns, they provide an effective and unobtrusive means of supervising public areas for fire protection. The D306 Remote Indicator Plate, included with the D297, provides a convenient means of verifying detector status. Install it anywhere within 500 ft (152 m) of the beam receiver (when using 18 AWG [0.75 mm 2] wire). The indicator plate has three LEDs to indicate normal, trouble, and alarm conditions, and test points to monitor the detector circuit.