I found these tiny voltmeters online and realized they'd make an outstanding improvement to my power blocks.
3D-printed material doesn't like to machine too well, especially carving on it with an X-acto knife, but I was
able to find just enough space to fit in a meter. This was totally worth the effort though, as it gives you
a clear indication of when you have power, gives you a reading on your voltage, and can even be used JUST as
a volt-meter when needed. This addition of very little cost and a little bit of effort basically TRIPLES the
value of the block. (I've updated all my bocks with the voltmeter)