Thrifco Plumbing 4408690 1/2 Inch OD X 3/8 Inch ID – 1/2 Inch MIP x 1/2 Inch FIP 24 Inch Long Yellow Epoxy Coated Stainless Steel Flexible Gas Connectors with EFV Gastop. Automatic Excess Flow Shut-Off Connectors: In the case of a gas rupture or a disconnect from the appliance, TSC EFV detects increase of gas flow and immediately shut-off the supply of gas. Gas flow is controlled only at the appliance where the problem exists. The valve will remain activated until the gas line is properly repaired. Automatically Activate Automatically Reset No Battery needed 100% Performance Tested Applications: Dryers, Boilers, BBQ Grills, Ranges / Ovens, Furnaces, Fireplaces, Space Heaters, Tankless Water Heaters, Rooftop Units, Manufactured Homes.