The D-Link HD MediaBridge Coax Network Starter Kit (DXN-221) is a simple solution for enabling network access by utilizing your home’s existing coaxial (cable) wiring. The HD MediaBridge kit includes two HD MediaBridge Coax Network Adapters (DXN-220), each with an Ethernet port and a coaxial connector to easily connect to available coaxial outlets. The D-Link HD MediaBridge Starter Kit (DXN-221) comes with two adaptors, each with a wired Ethernet port and coaxial F-type connector for bridging the two adaptors together. You simply connect one of the adaptors to your router and a nearby coaxial outlet, and the second between the network device and another coaxial outlet.

More info: D-Link