Air Aqua Self-Sinking Feeder Tubing Our lead weighted self-sinking feeder tubing is made of polyethylene plastic, with an encapsulated lead keel that keeps it submerged and securely in place. The tubing has a 1/2" inside diameter, and a 5/8" outside diameter. 

This self-weighted high density PVC tubing, is very flexible, tough and easy to install. It contains no metals, and requires no bricks or tie downs. Its thick wall does not allow kinking and discourages muskrat bites.