1/4" female national pipe thread. 1/4" FNPT M style plugs have a 1/4" basic flow size and air flow of 40 SCFM. 40 standard cubic feet per minute.
Milton S728 1/4" NPT Female "M" Style Plug 1/4" NPT- 2 Per Package
S728 MILTON 1/4 NPT FEMALE M STYLE AIR LINE COUPLER
MILTON 1818 1/2" NPT Female G-Style Plug
MILTON 1860 3/8" NPT Female G-Style Plug
Milton S-727 1/4" NPT Male M-Style Plug - 2 Pack
(1/10) Milton 732 3/8" Female NPT M Style Plug, Male body. - Fast, Free S&H.
