Eurolite QuickDMX Wireless Receiver

If you're working somewhere where there's no background 2.4GHz noise -- e.g., no wireless networks in your venue, no microwave ovens, and nothing else using the spectrum and you don't use more than five receivers, this is probably going to be great for you. They're not super-well made, but hey, they're cheap, and you can run them off the link power from your fixtures.

If, however, you have any RF noise around or you'd like to have a dozen or more receivers running, these are the absolute worst. You'll get random unexplained dropouts when one receiver gets confused by noise and all the receivers lock up for 1-5 seconds. Random channels will turn on and values will shift, and you'll have lights on when they shouldn't be. Unlike proper (and unsurprisingly much more expensive) wireless DMX gear, there are no debugging tools, and nothing you can really do to fix the problem. Stick to cables if it matters, or pony up for the good stuff.