This is premium beverage tubing that stays flexible even when cold. We use to sell a less expensive tubing but we were not satisfied with the performance on our own draft systems. We think it is definitely worth the little extra cost. Sold as a 100-foot roll. 3/16" is the best size for most beer lines under 9' in length. Ideally, 5' provides the correct restriction for serving beer in the 8-14 psi range. Technical Specifications:3/16" line provides 2.2 lbs of restriction per foot. Ideally pounds of resistance should equal pounds of applied pressure. 3/16" line holds 1/6 of an ounce per foot. Made from PVC. 7/16"OD