A.IF B.FH C.REG D.H90
A.IF-PIN B.NC-PIN C.REG-PIN D.REG-BOX
A.上為左旋螺紋,下為右旋螺紋 B.上為左旋螺紋,下為左旋螺紋 C.上為右旋螺紋,下為左旋螺紋 D.上為右旋螺紋,下為右旋螺紋