It's a Pace box. A google search for RNG150N autocompletes with the words "cable box" and the first article says it's a Pace box: "Get User Guides for Your TV Box - Xfinity" links to [Link: xfinity.com] where it's named as such.

Oddly, the second response to that search has someone asking if that model is a DVR, a subject that you bring up in passing.