These nitrogen cylinders are perfect for Nitro Stout of Nitro Coffee.  If you want to get a really nice creamy head on your stout or nitro coffee these disposable cylinders are the way to go. This cylinder will dispence a little over 40 liters of stout or nitro coffee.

Stout and nitro coffee requires high pressures (such as 2-3bar) so the product can push through the perforated disk that is inside our nitro spouts like this.  These elevated pressures require nitrogen because if CO2 was used at this high pressure the CO2 would absorb into solution and overcarbonate your beverage (if it's stored cold).  As a result nitrogen is necessary.

Nitrogen doesnt dissove into solution like CO2.  Even at elevated pressures only small amount of nitrogen will dissolve into solution.  It doesn't form the weak hydrogen bond with the liquid like CO2 and for that reason it does not dissolve into water based beverages easily like CO2.