SleepSafe 7 year carbon monoxide alarm is easy to use and self-contained. An essential product in all domestic environments such as homes, caravans and boats. Has a seven-year life span under normal operating conditions, and has a built-in internal battery. Should be installed by a competent person and is designed to protect individuals from the acute effects of carbon monoxide exposure. It will not fully safeguard individuals with specific medical conditions, however, if in doubt a medical practitioner must be consulted.