I just bought this set 10x and today will be returned. It is only suitable for very light smoke detectors, vulnerability are not Kleberpads magnet. My Mumbi radio smoke detectors are slightly larger than the average score (but not as large). Tonight from 6 MUMBIs are 5 down on the ceiling are the remains of DIY 2.10 smoke detector. The surface was smooth and clean, without dust, loose plaster, etc. In 2 cases, the pads have remained on the ceiling and smoke detector was on the floor.
My rating: moderately suitable for very light smoke detector.