BRK First Alert Battery Powered Smoke & Carbon Monoxide Alarm

Battery powered (2 AA batteries included). Electrochemical CO sensor – most accurate technology available for detecting carbon monoxide as compared to other sensing technologies. Provides 360ฐ of direct access to the smoke sensing chamber. Varying horn tone makes it easier for elderly with normal age related hearing loss to hear the alarm. Two silence features: low battery silence and alarm silence. Tamper resistant locking pins that lock battery drawer and/or alarm to mounting bracket. Loud 85dB alarm at 10 ft. Approved for residential or RV use.