First Alert Hardwired 120V Electrochemical Carbon Monoxide Alarm XL Big Green Egg Modular Feature an exclusive grooved cap

Feature an exclusive grooved cap design which prevents thread abrasion

Rust-proof aluminum retainer with a U-shaped vinyl floor seal to help keep out wind

large cushion type seal not easily damaged

Extra strong and extra durable

First Alert Hardwired 120V Electrochemical Carbon Monoxide Alarm XL Big Green Egg Modular Feature an exclusive grooved capFirst Alert hardwired carbon monoxide detector with battery back up. Features an electrochemical sensor which detects carbon monoxide gas and measures the concentration. Sounds a loud 85 decibel alarm when potentially harmful level is reached. 2 silent features; unwanted alarms and low battery silence. Instant test reset button. 9 volt battery included. Battery life varies according to use and application. Recommended for professional installation