Clear 1" ID / 1.25" OD vinyl tubing. Fits directly in the neck of standard or acid-style glass carboys (#7003, 7004, 7006, and 7007). Also fits Big Mouth Bubbler® Universal lids. Immerse the other end in a bucket of sanitizer or clean water to manage blowoff during primary fermentation. Available in pre-cut lengths of 3.5ft or 6ft.