CPS Hose Adaptor 1/4 Female X 5/16" Male AD78

Refrigeration and Air conditioning Charging line hose adapter

1/4" SAE Female to 5/16" SAE Male

1/4" SAE is the smaller size connection used on R407C / R134A / R404 / R22 etc

5/16" SAE is the larger size used on R410A & R32 Systems