The only gaskets designed for optimum performance with YELLOW JACKET Charging Hoses. Works with all refrigerants. Manufactured to strict tolerances to resist blow out. Made in the USA.
Yellow Jacket® Replacement Quick Coupler Gasket, Domestic
https://externalassets.unilogcorp.com/ASSETS/DOCUMENTS/ITEMS/EN/Ritchie_19005_Catalog.pdf- For use with 3/8 in hose