Compatible 4k Cameras

I have had a Xfinity alarm system with Cameras since they first hit the market many years ago. I am saddened in all this time they have never upgraded to a 4k camera and with Crime on the uptick I would like 4k cameras. I have read articles that state there are many cameras compatible and to look at Comcast/Xfinity to see which ones etc. But I can find a list. Would someone be so kind as to point me in the right direction.