[PVC Aquarium Tubing: The airline tubing is made of pure PVC material. It is really flexible and scratch-proof. Its thickened design allows for rough handling and repeated use. Multipurpose: The aquarium airline tubing is ideal for most basic aeration setup. Great for fish tanks aquariums hydroponics ponds water gardens siphon systems laboratories etc. Standard Size Airline Tubing: 13 ft. in length and 3/16" in diameter (4 mm in inner diameter & 6 mm in outer diameter). Work great on most common air systems such as oxygen CO₂ or other high-pressure systems. Kink-Resistant: The wear-resistant aquarium hose can be freely twisted without kinking. The smooth interior surface effectively prevents sediment accumulation and allows for smooth air flow. Safe & Reusable: The fish tank tubing is safe and reliable to resist cracking high temperature corrosion and leakage. Dependable for long-time use.]