Review on Philips Hue White Ambiance 4-Inch Dimmable LED Smart Retrofit Recessed Downlight - Compatible with Amazon Alexa, Apple HomeKit, and Google Assistant by Todd Roberts

For some reason these just didn't want to sync to the bridge, either from the auto-detection or from entering the serial number. Then 10 minutes later one connected and the other didn't. After a while, five minutes, the second is finally connected. Mechanical installation is tricky and they won't sit flush with the ceiling unless the presser foot goes through the panel on the inside and loses spring tension. Once that happens, the other two fall and the light dangles there. It really needs an adapter AND a much better installation guide. The writing is so small that I can't read it. There are no dimensions or mechanical images in the instructions.