Flexible Duct is generally used for handling air, airborne particles, fumes, and materials. Flex Duct is impregnated with neoprene, urethane, PVC, vinyl, or fiberglass compounds for long life and abrasion resistance. Fabric is reinforced with close pitch steel wire helix. Temperature range is from -75°F. to +500°F., for both positive and negative pressures. Lengths up to 50'. Standard sizes range from 1" through 24" I.D.