Titan2 Type HC is manufactured with a spiral wound strip of heavy gauge corrosion-resistant hot-dipped galvanized steel. For 3/8" through 1-1/4" trade sizes the core is constructed with a square locked steel strip with an integral copper-bonding strip enclosed within the steel convolutions. A rugged flame retardant flexible PVC jacket is extruded over the steel core. The jacket provides protection from liquids oil certain chemicals temperature extreme weather and sunlight.