Capable of up to 172 Mbps and upload speeds up to 131 Mbps based on Cable provider service. Good for streaming video and gaming on multiple devices at a time.Backward-compatible with Docsis 2.0/1.0. 10 x SB6121 Cable modem. The item "Lot of 10 Motorola Surfboard SB6121 Docsis 3.0 Cable Modem SB 6121 Tested" is in sale since Friday, October 26, 2018. This item is in the category "Computers/Tablets & Networking\Home Networking & Connectivity\Modems". The seller is "ssdeals-com" and is located in Chicago, Illinois. This item can be shipped to United States.