Description Ionization detector must be mounted to one of the B400 Bases Remote annunciator for 2 or 4 wire applications, use with any system sensor 400 series plug-in detector, fits standard single-gang electrical box Field test module for all of the system sensor 400 series smoke detectors Features • Unique dual unipolar sensor • Removable cover • Two visible LED's "blink" in stand-by • Sealed against dirt, insects, and back pressure • 3 year warranty • Built-in test switch • Low stand-by current • Tamper resistant • Designed for direct surface or electrical box mounting • 360 o field viewing angle of the visual alarm LED's • Optional recess mounting The 1451B-A ionization smoke detectors respond quickly to both fast flaming and slow smouldering fires. Unipolar dual chamber sensor has the sensitivity needed to quickly detect smoke, and the stability needed to avoid false alarms.