UnderDuct, SafeDuct & Corrosion Composites use Fiberglass reinforced plastics and are designed to be used anywhere corrosion resistance ductwork or other structures are needed. FRP can be used in many industries from mining, waste water treatment, processing, hospitals and much more. The benefits of using FRP are that it is strong, light weight, versatile, cost effective, factory assembled, eco friendly, and is available in custom shapes and fittings.