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.