New!! Magnetic Fastening Kit Quick and Easy Installation for Ceiling Mounted Smoke Detectors, Ceiling Mounted Wireless Doorbells or Motion Sensors EASY alternative to screwing a mounting plate to the ceiling (not the wall) NO mess, no fuss. No tools needed, no holes in your ceiling Compatible with most, if not all smoke alarms. Check if your smoke detector is not flat on the bottom, but recessed, this product may not be suitable. Holds up to 14oz (400 grams) of weight (may not be suitable for combo models) ** Warning: Area needs to be thoroughly cleaned prior to installation. This 3M product will not stick to dirt or grime! Please be sure to clean and dry the area first. Isopropyl or hot soapy water is best to clean the ceiling area prior to installation. Ensure area is thoroughly dry.