Coupler Size (in.). : 1/4, Male or Female: F, Swivels: No, Style: M, Pieces (qty.). Milton S213 A-Style Air Coupler and Plug Set - 1/4in. NPT, 5-Pcs. Milton S117 T-Style Pocket Blow Gun. Milton S600 Tuyau Fin 1/4ID 1/4NPT Laiton.