The Stout Spout extension can be used on any of the Nukatap / Intertap beer taps. It has a removable creamer/aerator disc inside that is specially made to serve beers infused with nitrogen gas, and allows the nitrogen gas to flow smoothly through the faucet with the beer to create a smoother, creamier beer.
Simply un-screw the regular nozzle and screw on the Stout Spout and use as you would a stout tap.