GENTEC Flashback Arrestors are specially designed to prevent personal injury and damage to equipment from severe flashbacks. GENTEC flashback arrestors are available for regulators, torches, and pipes Outlet connection: 9/16in-18LH and 3/8in-24LH are for Acetylene and Fuel gas models; 9/16in-18RH and 3/8in-24RH are for Oxygen models; 3/8in-24LH and 3/8in-24RH are available for torches and regulators only Sintered Metal Flame Arresting Filter quenches the flame from severe flashbacks Built-in automatic reset Check Valve prevents the reverse flow of gas by temporarily cutting off the gas FA10 and FA20 Series are equipped with a Heat Sensitive Cut-off Valve which automatically shuts off gas supply and cannot be reset FA23 Series is equipped with a Pressure Sensitive Cut-off Valve, which automatically shuts off gas supply and can be manually reset, and a Pressure Relief Valve, which relieves excess pressure and fumes in the event of a flashback