Plastic tubes are long hollow cylinders that hold or transfer liquids, gasses, or are used to hold and protect wires and cords. Acrylic tubes are scratch-resistant and have the same clarity and brilliance of glass, but are lighter and more durable. UHMW polyethylene tubes are strong and durable. They have a slippery surface and are easy to fabricate. PVC tubes are strong and serve as electrical insulators; they protect wires and other materials. Polycarbonate tubes are durable, resist impacts, and are easy to fabricate.