Create an effective drip system using 3/4 in. supply tubing (0.830 in. ID X 0.940 in. OD). Connect tubing to create a main supply line or attach smaller tubing to supply tubing to add a feeder line that delivers water to a low-flow drip-watering emitter. The red stripe on the tubing can be used to differentiate and identify different zones when there is more than one in an irrigation system. Unlike other manufacturers, NDS poly tubing is engineered in layers for durability using 100% virgin content for its outer and inner layers, with a middle layer of recycled content.