With Puncture Seal HD, small punctures and bead leaks are a thing of the past. When a puncture or bead leak occurs, microscopic, nontoxic polymer strands suspended in a liquid solution race to the air leak, adhering to the sides of the opening and builds a long lasting solid plug, impervious to water, mud and snow. However, Puncture Seal HD stays in a liquid form and is distributed evenly over the entire inside surface of the tire.