RJ45 2-1 Way Dual Female Port Connector Plug Splitter Adapter LAN Ethernet UK

NOTE: For 1 to 2 ports splitter: If you want 2 devices surf the internet simultaneously, you need to use 2 adapters as shown in picture 2; if you use only 1 adapter,ONLY THE RIGHT SIDE of the 1 to 2 port coupler WORK AS A CABLE CUPPLER and not as a Splitter.

eBay