This is standard clear tubing with a 1/4" ID (inner diameter) measurement. Customers have been known to use this as blowoff tubing, as it is claimed that it fits well into the grommets on the lids of fermenting buckets. It also works well in connecting certain tubing together by placing the 1/4" tubing inside a larger diameter that fits snugly. Whatever you need it for, we've got it!