Kidde BATTERY-OPERATED SMOKE ALARM UNIT, 9V, 8 KID-0914E

Battery-Operated Smoke Alarm UnitTest button allows you to quickly check unit's circuitry, horn and battery status. Chirp-style low-battery indicator. Red power-status LED. Protective dust cover. Battery: 9V (sold separately); Sensor Type: Ionization; Sound Level: 85db; Diameter: 3 7/8". Global Product Type: Smoke/CO Detectors-Smoke Detector Power Source(s): 9V Battery Mounting: Ceiling; Wall