Some brewers prefer the narrower 3/16" inch diameter, to minimize foaming by providing more flow restriction in shorter (5' or less) beer lines. 3/16" inner diameter tubing is used in our beer towers, and in all our draft systems. This tubing is 3/16" inner diameter by 7/16" outer diameter. This tubing will fit 1/4" hose barbs if you heat it in hot water before slipping over the fitting.
Note: The reviews below about the tubing being thin where placed when we were selling thinner 3/16" by 5/16" tubing. Thanks to your reviews, this has been corrected and the current tubing is a thicker 3/16" by 7/16". Sold per foot.This tubing has 3 pounds of resistance per foot. What does this mean? It means if you have a 4' beer line of this tubing, you have a total of 12 pounds of resistance in the line. Generally, this means setting your PSI on your regulator to the same 12 PSI figure will result in good beer flow, although setting it a bit lower can be preferable (to avoid carbonating the beer in the keg) if you do not need to fill glasses fast.