Review on TORCHSTAR 4 Inch Slim LED Panel Downlight: Dimmable, Ultra-Thin, ETL & Energy Star Listed, 5000K Daylight - Pack of 6 by Sarah Moore

I agree with @branzig using a 4 1/4" hole saw as they fit right in. Be sure to use some quick couplers along with a flex clamp to buy connectors to make the job even easier.I installed my clamp connectors and bought 4 post quick connectors which I also made before installing the boxes in the ceiling.Just leave the white connector hanging through the hole.Because they are for are designing a theater room, I chose the TP-LinkFast (HSS220) Kasa Smart Dimmer Wifi Switch to complete the setup.Quick and easy!As per many other reviews they are very bright (we went with the Warm White 3000K decided), but since this is a home theater they rarely turn on at 100% unless we're cleaning.