NOTE:2 RJ45 Splitter adapters must be used at the same time to allow 2 computers to access the Internet at the same time.This product is mainly used to solve the connection problem caused by insufficient wiring, and it can make 2 devices surf the Internet at the same time.Please refer to the instruction for connection. The RJ45 Splitter adapter divide original embedded Ethernet cables (8pins) into two groups (1236/4578). Two groups respectively transmit data with purely physical connection which don't have the function of the assign IP addresses. This RJ45 adapter is not a router or network switch,it does not have the function of the assign IP addresses.Widely used: By dividing the logistics network cable into 2 parts, the 2 devices can be online at the same time, such as: laptop, TV box, router, camera. Plug and play, no need to set. The speed of each cable groups (1 and 2) can only reach 100 megabytes.And the signal transmission of two cable groups are not interfered with each other.RJ45-A interface port"1" is corresponding to RJ45-B interface port"1".RJ45-A interface port"2" is corresponding to RJ45-B interface port"2".They can't be reversed. Use a pair of adapters when installed.Network cable is 8pins, normally only conneted four pins(1236). A switch is connected to splitter A, and then connecting splitter B the terminal socket, so it can use another 4pins(4578).When there is only network cable in the wall, two computers can be connected simultaneously. NOTE: When used in a single adapter which can be used as extension cable, but ONLY Port No.2 can be used.