WARDFLEX® MAX is a corrugated stainless steel tubing (CSST) system designed to distribute fuel gas in residential housing units and commercial structures. WARDFLEX® MAX has been engineered, tested and certified to meet the performance requirements of American National Standard for Fuel Gas Systems Using Corrugated Stainless Steel Tubing, ANSI LC-1. As such is acceptable for use with all recognized fuel gases, including natural gas and propane. Ward Mfg WARDFlex® Corrugated Tubing, 3/4 in Nominal, 0.98 in Outside Dia, 250 ft Length, 0.01 in Wall Thickness, 25 psi Working, -40 to 165 deg F, 304 Stainless Steel, Black, ANSI LC1, ASTM A240/E84, CSA 112940, IAPMO 3353, ICC ESR-1879, UL R18357, Domestic