Not all brands of draft beer use the same type of valve in the keg. Each distinct “system” requires matching the appropriate keg coupler to the keg valve. In the U.S., there are eight different “systems” in use:
“D” System (American Sankey): Most North American beers. Used by breweries such as: Budweiser, Coors, Miller, Labatt and Molson.
“S” System (European Sankey): Many import beers. Used by breweries such as: Heineken, Becks, and Amstel Light
“A” System (German Slider) : Many German beers. Used by breweries such as: Spaten, Warsteiner, and Paulaner.
“M” System: Is recently introduced to the U.S. market. Body is the same as the German Slider, but the probe configuration is unique. Used by breweries such as: Schneider, Aventinus, and Einbecker.
“G” System: This system gets its name from the English developer, Grundy. Used by breweries such as: Bass, Boddingtion’s, Caffrey’s and Anchor Steam.
“U” System: This system takes its name from the English manufacturer UEC. Used by breweries such as: Guinness and Harp.
Twin Probe: Limited use by some craft breweries.
Home Brew: Ball lock fittings used for home brew tanks.
So Suzy, you definitely need to know which type of coupler you need to match up to the right keg tapping equipment.