Compared to double-wall duct construction with perforated metal lining, the CertainTeed ToughGard Ultra Round spiral duct liner offers cost and weight savings as well as simplified fabrication and installation. Ultra Round provides improved acoustical performance and has a tough, durable and cleanable air stream surface with an EPA registered antimicrobial agent.

CertainTeed Corp., P.O. Box 860, 750 East Swedesford Road, Valley Forge, PA 19482; (610) 341-7000; fax (610) 341-7777; www.certainteed.com.