This 5/16" inner diameter tubing is most often used for racking and transferring. It will fit snugly onto a regular auto-siphon or racking cane, as well as the mini auto-siphon. Though it can be difficult to get off, some people prefer the tighter fit of the 5/16" tubing to the looser 3/8" tubing because the line does not come off or cavitate during transfers as easily. Whatever you prefer, we've got you covered!