Check the listing for details. ARRIS (16x4) SURFboard DOCSIS 3.0 Cable Modem. Approved on Xfinity Comcast [LN]™. Condition: Open box. Listed at 29.89 USD. The ARRIS SURFboard SB6183 cable modem is a DOCSIS 3.0 modem with 16 downstream x 4 upstream channels. It is a top tier option for cable internet speed plans up to 400 Mbps and is approved for use with Cox, Spectrum, Xfinity and other major U.S. Cable internet providers. Save on monthly modem rental fees by purchasing your modem today. This is NEW but open box. Thank You for looking. R3