Dealsplant 1:2 lan splitter adapter 1 input 2 output 1x2 Splitter Adapter 1-Port Female to 2-Port Female Socket Y Adapter Extender Plug LAN Network Connector for CAT5, CAT5E, CAT6, CAT7 - Black Lan Adapter

This adapter can be split into two network cables, but the real use of only one can be used is that even if both computers are inserted at the same time, there will be only one connection, of which the main adapter is the use of sub-lines