Milton S-99705 - 1/4" FNPT M style safety couplers are easy to use. Simply push once to stop airflow, twice to release plug. Safety couplers prevent possible injury or damage due to accidental disconnects. OSHA required in certain areas and applications. M style couplers have a 1/4" basic flow size and offer air flow of up to 36 SCFM. Maximum pressure of 300 PSI. Red button color for easy identification.