Excellent product. Nice and bright. Fits standard 125mm holes.
Do note these are the larger size holes though, not the little 70mm or 90mm your 12 volt downlights use.
This is a really great light and the control with Alexa and the Hue Bridge is fantastic.
Start your smart home journey today with Philips Hue white ambiance Aphelion LED downlight. It's a connected light that offers cool daylight to warm white light in a smart lighting system. Set your ambiance with effortless dimming and customize your daily routines with light recipes. Enjoy the convenience of a wireless lighting system which offers optimal control with third party apps. With integrated LED technology, Philips Hue white ambiance Aphelion LED downlight provides up to 20,000 hours of long lifetime, up to 80% energy savings and reflects objects closely in their natural colors.