I don't know why people are giving this product 4/5 * when it clearly has sw implementation problems. The actual device is nice, small with a convenient magnet, but the sw which surfaces the functionality is TOTALLY deficient. I have mine on the ceiling and trigger is ~1m horizontal distance. The BIG issue is how you get it to trigger, you can only select 1 room, and a day or night schedule. Say you want it to trigger between 23:00~07:00hrs, and not do anything outside this time, well you can but if the trigger room lights are on they will switch off if the sensor is triggered. So it does not do nothing it switches OFF the lights between 07:00-23:00hrs, and ON 23:00~07:00hrs. So 21hrs you're having dinner, the cat triggers the sensor and 1 minute later the lights go out. That's how poorly implemented this is, and I don't have a defective unit. In order to get this working you have to install the "Do Not Disturb My Scene" Hue Labs Formula http://labs.meethue.com/formulas/huelabs/do-not-disturb-my-scene but even then it has issues.