20 Series Quick Couplers (pneumatic, air) up to 300 psi connect with Industrial Interchange Nipples. Couplers are manual sleeve, single shut off couplers that mate with nipples conforming to A-A-59439 (MIL-C-4109F, ISO 6150-B) standards. 20 Series couplers have steel, tubular style valves that deliver high flow with minimal pressure drop. An integral sleeve guard helps to resist accidental disconnection when in use.