The AmeriVent® by Duravent cap is the first engineered vent cap to gain recognition across the country for its performance. Millions of them are now installed on homes and business structures to protect against wind conditions that can cause waste gases to spill back into the structure through the appliance draft hood. The AmeriVent® by Duravent cap is UL-listed, and its patented design of ports and baffles keep rain and debris out of the vent. In addition, AmeriVent® by Duravent caps permit termination of vents at the minimum height necessary above the roof surface.