Kidde long life carbon monoxide alarm with sealed 10 year battery kidde 10lldco this carbon monoxide alarm from kidde has a host of excellent features making it ideal for living areas as it can also be installed on a wall ceiling or used free standing on a table or shelf one of the many features is the unique water based co electrochemical sensor with an alarm memory meaning that a red led will flash every 60 seconds to indicate a co event has occurred there is also the co quick test