This technique works so well I bought two. Stupidly I tried to connect without reading the instructions = doesn't work. Too easy after 20 seconds of reading. One block is an input transmitter and the second block is a receiver with an output signal. Once you've got the input/output pair set up properly, all you have to do is add a signal and you're good to go. The devices are little white boxes and I haven't noticed any interference or performance issues. A strong buy recommendation with a stronger endorsement of usability.
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