Grow1 Black Vinyl Tubing, 3/16 Inch (ID), 1000 FeetGrow1 Black Vinyl Tubing Made from strong and durable vinyl material, these tubes are available in a variety of sizes and lengths, great for use with air or water. The tube walls are thick and flexible, and you may choose between the 100% opaque black vinyl, which prevents algae growth, or the clear vinyl that allows for complete visibility. If you are using accessories such as basket drippers and air stones use (ID) 3 16'' instead of (ID) 1 4''