FORTRESS is a precision engineered system of prefabricated PVC duct and fittings which conceals and protects exposed refrigeration linesets, electrical cable/telephone wiring and water or drain pipes. It comprises extruded PVC duct plus a full range of 16 injection molded Polypropylene fittings, all of which meet the requirements of the current UL -94 V-0 specification and are suitable for temperatures from -4 to 140 degrees F.