This tubing was designed for use in the Multi Flow Hydroponic System. It's a soft vinyl that allows a tighter bend radius without kinking like standard vinyl tubing. This makes positioning the Multi Flow pots much easier and avoids the possibility of cutting off the water flow to your plants. 3/4" I.D. for hydroponics projects. Fits most pumps. Black color will keep light out and stop algae from growing inside. 3/4" ID 15/16" OD.