There is water in it, the water stays in the radiator thing and the brake oil will run in tubes through the water to keep it cool. unless your doing alpine runs with the brakes on full i don't think thats really worth the hassle. I would love that brake though! i'd swap my liver for a set.

 is this the one that has 3 brake pads in?
it has two on the out side like normal and one inbertween the discs?

 i heard they used to squeal like hell, interesting concept though, pity its just too advanced to be practical but nice try shimano

 I guess, it's making mega braking power )

 cool concept but overkill for mtb

 Yeah I was looking at that, looks like a heat-sink; radiator style... I fail to see how how the water is pumped though...

 too strong... thats like motorcycle status

 thats preety sikk

 What's the other dongle thing? Colling unit?

 looks heavey

 holy fucking shit

 thts just stupid in my opinion....dont hate my opinion, but its just useless and completely un-needed for mtb