That's for manual transmissions. Though it possible to hook up a clutch to an automatic, why would you even want too?
seems to be working pretty good for TS & Smiths trucks, the 2 fastest 4x4 diesels around.
From the In cab videos it looks like their spooling on the clutch, dump it on the launch & hand shifting thru the gears(individual shifters for each gear like a lenco)