This is a great little wireless system: I've used a few and these are sturdy, small, and reliable. I hardly ever notice when they're in my guitar vs. a standard cable; the tone holds up just fine.

Had these a few years and no longer need: I don't have the box, but I've got a micro USB cable that works to charge them (you plug it into the "receiver" one with two lights, then put the 1/4" from the other one inside that one, and they both charge. It makes sense once you see/use it).