Smith Equipment Flashback Arrrestors  Stock # H753These will go between the regulator and hose. (Regulator Mount)Designed to help prevent accidents caused by reverse gas flow or flashbacks Built-in check valve protects against reverse flow Brass construction for long life 100% tested for reliability and performance color coded by gas service for easy identification Made in USACapacity:Welding: 3/8" Cutting: 12"Maximum inlet pressure:Acetylene: 15 PSIG Other Fuel gases: 22 PSIG Oxygen: 145 PSIGHose size: 9/16" - 18 std. B connectors