This adapter is a passive Ethernet splitter designed to solve wiring constraints by enabling two devices to access the Internet from a single Ethernet line through a physical tapping method. It divides an embedded 8pin Ethernet cable into two groups: 1236 and 4578. Each group carries data through a purely physical connection and does not provide IP addressing or routing functions. It is not a network router or a network switch. The speed of each cable group can reach up to 100 megabytes. The data paths of the two groups operate independently and do not interfere with each other. RJ45A interface port 1 corresponds to RJ45B interface port 1, and RJ45A interface port 2 corresponds to RJ45B interface port 2. The pairings are fixed and cannot be reversed. Key benefits Enables two devices to share a single Ethernet link when wiring is limited or additional cables are not feasible. Passive, no power required and no IP configuration needed; simple plugandplay with standard Ethernet setups. Two independent signal paths provide up to 100 megabytes on each path without cross‑path interference. Not a router or switch; preserves the original Ethernet signaling on each path. What it works with Standard RJ45 Ethernet cables and connectors. Existing Ethernet outlets where a second device needs a connection without adding network hardware. Scenarios where IP addressing and routing are handled by other devices in the network (this adapter does not assign IP addresses). Use scenarios Home or office cabling constraint: connect a computer and a smart device (such as a printer or media player) to a single wall jack without running extra cables. Temporary testing or lab setup: quickly connect two devices to the same Ethernet line for monitoring or benchmarking without a router or switch. Retail or small business environments: share one Ethernet outlet between two devices in tight spaces where additional cabling is impractical. Specifications Cable type: standard 8pin RJ45 Ethernet cable Split groups: 1236 and 4578 Data paths: two independent physical connections Speed: up to 100 megabytes per group Interfaces: RJ45A and RJ45B; fixed 1to1 mapping (1 with 1, 2 with 2); not reversible Function: passive adapter not providing IP addressing or routing functions