A sixtel keg is 1/6 of a full keg of beer. Sixtels are also called sixths due to their size. A sixtel keg is similar to a corny (cornelius) keg in size, however it will have a commercial style connection (rather than ball/pin lock fittings).
A sixtel keg is equivalent to .16 barrels, and holds approximately 5.16 gallons.
Sixtel kegs are commonly used by craft breweries and those serving high gravity beers.