Smoke Alarm Battery Chemistry Alkaline Battery Location Side Battery Locking Pin Yes Battery Size 9V Communication Protocol Not Applicable Compatible With BRK Hardwired Alarms Detector Type Smoke Detector Features Latching Alarm Indicator Single Button Test-Silence Optipath 360 Technology for 360 Degrees Direct Access to The Smoke Detectors Perfect Mount Dust Cover Includes Battery Number of Tandem Detectors 18 Power Source Hardwired Sensor Type Photoelectric