I continue to ba amazed at how they could put it on the market when it had a range of 40 ft with Canon's top of the line Flash. They must have known this. Then, there was one fix after another, shields, modifying the flash to add capacitors, then flashes failing. That shield will insulate a flash, and heat dissapation is a problem without it, if you use a flash really hard, its life will drastically diminish due to overheating, and this makes it even worse.
They continue to make excuses that they had no choice about RF frequency, while other manufacturers use other frequencies and have units that work well.
Those shields should have been a temporary fix while they redesigned the unit, but they continue to supply klutzy shields.
Also, do not expect it to work with any new flash that Canon releases. It might, but then again, it might not.
I have stayed far away from them.