Used (~1 year) Netgear CMD31T DOCSIS 3.0 High Speed Cable Modem. Additional details and technical specifications can be found at the official Netgear link:

http://www.netgear.com/service-providers/products/cable/modems/cmd31t.aspx

The unit works with Comcast, Charter, Cable Vision, Cox, Time Warner Cable and others. I can personally confirm that it does indeed work with Comcast and I used it for a full year when I had their service. It is an extremely fast and reliable modem. I only stopped using it because I moved and switched to a different provider. Please feel free to email with offers.

Cash only.