David Clarke H10-13.4 as stated above.
Except if it doesn't fit your head!
I have a Lightspeed Zulu 2 and really like it. I've just had to buy a new one, because my original one was stolen. I looked briefly at the PFX, but declined. It is more expensive, takes four batteries and the dealer told me the battery life was shorter. However, the main reason I decided to stick with the Zulu 2 was that the battery/control box on the PFX is about twice the size of the one on the Zulu 2 - it's like a brick.