Key Features 8mm Internal Diameter Sinking Airline Weighted to allow for positioning on floor of ponds and aquariums without the use of weights Black colour assists with hiding the tubing away as it blends into the pond base Made from tough rubber that is durable and will not kink 5 Metre precut length - Note if ordering more then 1 they will arrive in 2 precut packages. Aeration in a fish pond is an essential part of the eco system. By providing adequate air, the water remains rich in oxygen that benefits the fish and gives them the healthiest environment to live in. The Kockney Koi Sinking Airline has been designed to sit along the natural contour of the pond side, eliminating the need for weights to keep it in place. Unlike standard airline, the tubing is make of thicker and heavier material, making it easier to sink and sit in place. It is also resistant to UV light exposure and is tough external material makes it resistant to kinks and damage The airline also blends in with the