This device works great, but it took some fiddling to get it working. The "Func" button is actually a power button. If you press and hold it for about 3 seconds, the device will turn on. A slider on the side (I thought it was the power switch) toggles the mode from RJ45 to HDMI. I tested it with both RJ45 and HDMI, it works great. There are some black adapters that cover the RJ45 to allow a smaller plug to be used, so just remove them to test the RJ45.