Nighthawk Plug-In Carbon Monoxide Alarm with Battery Backup Brand New Peak Level Button ? Displays the peak CO level recorded by the alarm since it was last reset or unplugged Test Button Functions ? Tests the unit for proper operation and resets the Carbon Monoxide alarm LED Operation ? Blinking dot in lower right corner of display denotes normal operation Ten years after the initial power up, this alarm will ?beep? two times every 30 seconds to indicate that it is time to replace the alarm. NOTE: This CO alarm is not battery operated. However, these alarms are equipped with 9 volt battery backup ? the 9 volt battery is to supply short term back-up during a power outage. Please refer to photos to access Items Condition Shipping Policy ? If you are International Buyer - contact us before buying Payment Policy ? Item will be shipped immediately on the same or next business day of receiving full payment Return Policy ? Items Condition is clearly stated in the description ? Actual Images of item are shown ? Returns ACCEPTED FOR 7 DAYS, BUT THE BUYER IS RESPONSIBLE FOR RETURN SHIPPING If you have any problems or questions - contact us right away and we will do our best to resolve the problem. Massages are answered from 9:00 AM to 5:00 PM EST Monday through Saturdays Good Luck and Happy Buying basement