3/8 FNPT P style couplers have 8 locking balls for better retention of plug. Has a maximum of 300 PSI with a basic air flow of 3/8. Heavy duty steel body has a Buna-N seal. Available air flow of 68 SCFM. Product Features:3/8 female national pipe thread3/8 Basic flow size Maximum of 68 standard cubic feet per minuteMaximum inlet pressure of 300 pounds per square inchBuna-N seal