It's the cometic Phuzion head gasket setup. There's a pretty good article on it in the March 2006 issue of Hot Rod.

Essentially, it's a cometic head gasket with the cylinder bores opened, and then a gas filled O-Ring dropped in place of the removed fire ring, and the head gets clamped on as normal. Essentially, as the motor warms up, the gases in the O-Ring expand thus expanding the o-ring, and you run an extremely small chance of actually lifting the head high enough to cause gasket failure. No notching of the block around the bores (like in a traditional o-ringed block) necessary.

Anyone seen this or have any comments or experience??? Seems like a sound idea. I wish I had a link but cometic doesn't show it on the website.

 

I saw the same article and I plan to use them.

 

I was thinking about trying them out too, but they're pricey at $200 per head. That's definitely a chunk of change, but people are already having good luck with the cometic head gaskets, so as long as the O-Ring proves to be worthy, could be a very nice option.