Equipped with an electrochemical carbon monoxide sensor, a test switch, an 85-decibel horn, and a red LED power indicator, this carbon monoxide detector warns you to the presence of carbon monoxide.. Hinged Cover Design - Allows for fast, easy installation and battery replacement. Silence Feature - Silence unwanted alarms. Test alarm with the same button.. Tamper Resistant Locking Pin locks alarm to to base to prevent removal of battery. 9V alkaline battery included. 10 Year CO Sensor/10 Year Alarm Life. 10-Year Limited Warranty