Fermtech's now-famous Auto-Siphon is the easiest and most efficient way to move beer or wine from one vessel to another, and makes bottling a snap. Simply pump the inside arm of the siphon to start, no need to suck on the end like in the old days.
3/8" model is regular size and uses 5/16" or 3/8" tubing. 1/2" model is large size and uses 1/2" tubing. Mini Auto-Siphon is for 1-gallon glass jugs, and also uses 5/16" or 3/8" tubing.