DOLPHIN Life Rings are the only Life Rings manufactured in North America with U.S. Coast Guard, Canadian Coast Guard and DOT approval. All Dolpin Life Rings are rigorously tested and monitored by the Underwriters Laboratories of the United States and Canada. The Ring bodies are warranted for seven years under all climatic conditions and are resistant to fire, oil and gas. The hard shell prevents tearing and ripping and is virtually vandal proof. The design allows for easy rope replacement should the rope become damaged, thus ensuring the integrity and continued certification of the Ring. Dolphin Life Ring Buoys are roto-molded for strength with a polyethylene shell and filled with closed cellular foam for long life under extreme marine conditions. They conform to all standards up to and including S.O.L.A.S standard 7483.