Review on 🔌 RJ45 Splitter Connectors Adapter - 1 to 2 Ethernet Coupler for Cat5 Cat6 - Dual Socket HUB Interface - Connect Network LAN Internet - 2 Pack (CAN'T RUN BOTH SIMULTANEOUSLY) by Joshua Paulson

The description implies that they reflect all 8 connectors. A photo says no. Well both are correct, in my experience I bought two pairs and got two ("Cat/5A/6A") reflecting all 8 pins and two ("A/B"), which combine the first two pairs. (the only ones used in many ethernet connections) so it is (in many cases) possible to have two physical ethernet connections on the same cable using an "A/B" connector on each end of that cable to attach. Mirrors were what I wanted to experiment with RS-485, but I could have used others.