The Ei146RC is an Optical Smoke Alarm with 230V AC mains power supply and 9V alkaline battery back-up. It is ideal for location in the hallways and living rooms. Photoelectric sensor 230V AC supply with 9V battery back up Easi-fit base Hardwire interconnect Remote Test, Locate and Silence compatible Large Test/Hush button Memory feature Integrated piezoelectric sounder EN 14604:2005