Milton's G-Style couplers and plugs are the highest SCFM rated and are used in applications that require over 60 SCFM. These 1/2 inch MNPT G-style plugs are offered in 2 different sizes (0.125 or 0.375 critical profile dimension tip sizes), but both will function the same with G-style couplers. 1/2 inch MNPT and basic flow size, with a maximum air flow of 99 standard cubic feet per minute and 300 PSI max inlet pressure. Made of durable case-hardened steel and plated to resist rust.