Fire Hose Flow Valve Department Coupler #14

Description

Exact adapter in pictures.  Aluminum.   Any help in a proper ID will be appreciated.  I do not know how to properly measure - see pictures.
Look close at pictures.  The threads on this piece are coarse,  (some  valves use fine)   I sell surplus - know nothing about application.
More "Fire" adapters and Humat valves in my store category OTHER or search my store for FIRE
shed blue