First Alert SA511CN2-3ST Wireless Interconnected Smoke Alarm with Voice Location, Battery Operated, Pack of 2 , WHITE - Smoke Detectors - Amazon.com
CHZHVAN Interconnected Smoke Detector, Wireless Smoke Alarm with 10 Year Battery Life, Photoelectric Sensor Fire Alarm with Large Test Button and Low Battery Warning, Fire Detector for Home, Bedroom - Amazon.com