First Alert SA521CN-3ST Smoke Alarm Battery Operated 120 Volt Winter_Items Wheel Diameter: 4-1/2"

Wheel Diameter: 4-1/2"

Remains flexible and absorbs the expanding and contracting seasonal movement of the wood

For age 3+ years

Strike can be mounted either on the gate or the post

Color : White/Brown painted

First Alert SA521CN-3ST Smoke Alarm Battery Operated 120 Volt Winter_Items Wheel Diameter: 4-1/2""FIRST ALERT" SMOKE ALARM 120V AC DC Easily expand an existing interconnected 120V AC system by replacing one alarm in the series with this alarm Add additional battery operated First Alert Onelink enabled alarms to expand without wires Photoelectric smoke alarm reduces nuisance alarms Alarm and low battery silence feature 10 year limited warranty