The H450EN is an easy to use and reliable self-contained Carbon Monoxide alarm. Designed for use in all domestic environments such as homes, caravans and boats. Batteries supplied and pre-fitted in alarm. IT IS NOW PART OF UK BUILDING REGULATIONS FROM 1st OCTOBER 2010 THAT A (CO) ALARM IS FITTED IN TO A DWELLING WHERE A NEW OR REPLACEMENT FIXED SOLID FUEL APPLIANCE IS INSTALLED. ( Document J ) Building Regs 2010 GUARANTEE The H450EN has a 6 Year GuaranteeCONSTRUCTION H450EN has a superior electrochemical cell sensing technology Automatic sensor adjustment function ensures complete accuracyAPPROVAL H450EN is approved to EN50291:2001INSTALLATION The H450EN should be installed in the same room as the appliance. On the ceiling at least 300mm from any wall or, if it is located on a wall, as high as possible (above doors and windows) but not within 150mm of the ceiling AND between 1m and 3m horizontally from the appliance.