You don't have to rent a cable modem from Comcast! You can use your own and save yourself money by not paying their ridiculous monthly rental fee. I was using this modem with Comcast / Xfinity with absolutely no issues at all. I switched to a different internet provider and this modem isn't compatible with them, so I'd like to sale it.
Even if you don't buy mine, at least get yourself one and quit giving Comcast any more money than you have to.
Here's some info about it.
DOCSIS 3.0 High Speed Cable Modem
Channel bonding of up to 24 downstream channels and 8 upstream channels provide data rates up to 1029Mbps for downstream, and 206Mbps for upstream
CableLabs Certified® DOCSIS 3.0 technology delivers speeds 24x faster than DOCSIS 2.0*
Gigabit port ensures ultimate fast transfer speeds
IPv4 and IPv6 dual stack
Quick and hassle free installation
Eliminate monthly rental fees
Compatible with major cable ISPs, including XFINITY from Comcast, Cox, Spectrum and more.