Du-Bro Nitro Line Silicone Fuel Tubing (Yellow - 2ft) Part No: 2230. Nitro Line comes in 6 hot colors to add a great look to your vehicle. Our tubing is made from high quality 3/32" (2.38 mm) ID silicone that is durable and will perform just the way it should. With no kinks when coiled and superb gripping on your fittings, Nitro Line is the real professionals choice. 2 ft (0.6096 M) lengths.