The FireAngel RF Alarm Push Fit Ceiling Base with Wireless Interlink RF-BW-T is a reliable smoke heat combined alarm base that is easy to install. With a diameter of 139.6mm and a depth of 38.9mm, this ceiling base is designed to fit seamlessly into any room. Manufactured in the United Kingdom, this white-coloured unit operates on a single battery and is a essential component of a comprehensive home security system. The wireless interlink feature ensures that if one alarm detects smoke, all alarms in the vicinity will sound to provide maximum protection for you and your family.