Sold by the foot. Use for long draw systems and as an entry line to a draft box.,,Technical Specifications: 3/8" line provides .20 lbs of restriction per foot. Ideally pounds of resistance should equal pounds of applied pressure. 3/8" line holds 3/4 of an ounce per foot. Made from PVC.,Outer diameter of tubing is approximately 5/8",Quantity ordered will be shipped as a single uncut length. Maximum length available is 100 ft.