The Motorola ARRIS SURFboard SB6121 is a high-speed cable modem designed to deliver internet performance up to 172 Mbps. Featuring DOCSIS 3.0 technology, it provides four bonded downstream channels and four bonded upstream channels, allowing for efficient data transfer and reduced congestion during peak usage times. This unit is compatible with major US cable providers including Comcast/Xfinity, Cox, and Bright House Networks, making it a versatile choice for users looking to avoid monthly modem rental fees. The modem's compact, vertical design helps minimize its footprint on your desk while providing clear LED status indicators for power, receive, send, online, and link status. While newer DOCSIS standards exist, the SB6121 remains a reliable, budget-friendly option for standard high-speed internet plans. This item comes in its original retail packaging, which shows light shelf wear but suggests the contents are well-protected.