ARRIS SURFboard WIFI cable modem model SBGB8300DOCSIS 3.1 Gb. Used for 8 months. Asking $75. Retail price is about $250.
This modem is designed to be compatible with most major U.S. cable internet service providers, optimizing Gigabit plan speeds and beyond for smooth video streaming, online gaming, and file transfer experiences. Additionally, the SURFboard SBG8300 has a built-in wireless router that can transfer up to 2350 Mb/s over the 2.4 GHz and 5 GHz bands with 802.11ac Wi-Fi compatible devices. There are also four Gigabit Ethernet ports available for wired devices. Simply connect your cable service's coax cable to the SURFboard SBG8300 and use the ARRIS SURFboard Manager App to configure your network from your mobile device.