The Fermtech Auto Siphon is a handy tool used in transferring and racking. It is self-priming, so starting a siphon is as easy as pumping this a few times and letting your beer or wine flow! This one will take either 5/16" or 3/8" ID siphon tubing, though the 5/16" ID tubing will fit more snugly and be more difficult to remove. If you're sick of trying to manually starting a siphon with a racking cane, the Fermtech Auto Siphon is for you!