Universal Security Instruments CD-9775 9-Volt Battery Operated Combination Ionization Smoke and Carbon Monoxide Alarm Combines separate sensors to detect smoke or carbon monoxide Silence feature - convenient silence button with automatic reset allows you to temporarily override an alarm - ideal for cooking smoke and fireplaces and eliminating nuisance alarms The quick-draw pull-out drawer makes battery replacement easy This unit includes 3 LED alarm condition indicators and is equipped with a loud 85 dB horn alarm Fast and easy installation