Replacement rubber gaskets are for female couplings or adapters. These gaskets will fit National Hose thread "NH", National Standard Thread "NST" or National Pipe Straight Hose "NPSH".
Forest Service Spec 5100-190
National Stock Number 5330-00-720-2621
This Wildland Fire Equipment gasket is used by the U.S. Forest Service (USFS), Bureau of Land Management (BLM), Bureau of Indian Affairs (BIA), U.S. Fish & Wildlife Service (USF&WS), National Park Service (NPS), State and Local governments, and other Forest Service–sponsored participants in the government-wide wildland firefighting effort.
This is the same gasket found in the Defense Logistics Agency (DLA) Wildland Fire Equipment catalog or Fedmall.mil.