Pro-Flex Corrugated Stainless Steel Tubing (CSST) makes installing gas piping for natural gas or propane gas appliances quick and easy. The Pro-Flex patented fitting system and flexible tubing enables installers to reduce installation time and to eliminate the equipment needed to install gas piping in new or existing construction. Pro-Flex CSST can supply gas throughout a home or commercial building. Route it through walls, floor or ceiling joists, or outside to a variety of appliances.