Approved for Cox, Spectrum and Xfinity internet along with other US cable internet providers. Is NOT compatible with ATT, CenturyLink, Verizon, Frontier or other Fiber Optic, DSL or Satellite internet service providers. | Does NOT include Wi-Fi and Does NOT support cable digital voice service. | Save Money: Own your modem and save. Reduce your cable bill up to $168 dollars per year in cable modem rental fees (Savings vary by cable service provider). Certified for use with most U.S. cable internet service providers. For a complete list see additional details below. | Modem Technology: DOCSIS 3.1 is the newest technology available from cable internet providers. Its 10x faster than DOCSIS 3.0, provides better security, reduces lag while gaming & enables multi-gig networking (ability to run fast speeds on your copper cable from your internet provider). | Simple and Secure Set-up: Plug-in the device, download the SURFboard Central App, and follow the instructions to activate the modem. Connect to a Wi-Fi router for networking. | Compatibility: The SURFboard S33 is compatible with major U.S. cable internet providers including Cox (Gigablast), Spectrum (Internet Gig), Xfinity (Blast!/Extreme Pro) and others. It's approved for cable internet speed plans up to 2.5-Gbps. Check your Internet Service Provider (ISP) website to confirm compatibility.