This A-A-59326-compliant 316 stainless steel dust plug has a male adapter connection with a four-inch coupling size. The coupling component is a plug with a DP coupling type and has a plug outside diameter of 4 3/4 inches. This dust cap can be used in citric acid, fuel, hydraulic fluid, and general-purpose applications. Its working temperature is 0 Degrees F to 200 Degrees F, with a maximum operating pressure of 100 PSI.