The First Alert CO250RVA RV-Approved CO Alarm is a state-of-the-art carbon monoxide alarm designed to provide early warning of the presence of carbon monoxide. It features an electrochemical carbon monoxide sensor, an 85dB horn, a full-function test switch, a red LED light that indicates DC power or alarm, and a 9V alkaline battery. This alarm has two silence features. Low Battery Silence temporarily silences the low battery chirp for up to eight hours. Alarm Silence silences the alarm for several minutes. It also features a tamper-resistant locking pin that locks the alarm cover to prevent removal of battery. Perfect for RV use. Original BRK Replacement CO Alarm â Replaces the original BRK alarm that came with your RV (model CO250RVA).Hinged Cover Design â Allows for fast, easy installation and battery replacement. Silence Feature â Silence unwanted alarms. Test alarm with the same button. Tamper-Resistant Locking Pin â Locks alarm to base to prevent removal of battery.• Approved for use in recreational vehicles• 9V alkaline battery included• 10-Year Limited Warranty Red LED light indicates DC power or alarm Low Battery Silence & Alarm Silence features Includes 9V alkaline battery | First Alert CO250RVA RV-Approved Battery-Powered CO Alarm