LED Lights - Green for normal operation, Red for alarm, Amber for Error.Digital Display - Displays the level of carbon monoxide the unit is sensing. The unit updates this reading every 15 seconds.10-Year Sealed-in Lithium Batteries -Unit will continue to operate for 10 years. Alerts user to replace unit after 10 years of operation.Peak Level Memory - Displays the highest CO concentration measured since the last reset.Test/Reset -Tests CO alarm circuit operation and allows you to immediately silence the alarm.
