John Guest 3/8" Polyethylene Tubing for Drinking Water Filtration Systems (blue) - 500 ft. roll ﾠﾠ John Guest tubing provides the benefits of a wide range of temperature and pressure suitability, and is made from non contaminating materials. Common applications are in water purification, water conditioners, ice makers and misting systems.ﾠ 3/8" for increased waterflow compared to 1/4" ﾠ Features: Linear low density polyethylene Suitable for cold and intermittent hot water applications Broad chemical compatibility FDA and NSF certified Strong, flexible and robust