Do you know the D-ring on a grenade?

D-rings can also be used on windbreakers.
In fact, the first D-rings were worn on the belts of windbreakers.
They were mainly used by soldiers to hang light objects, such as maps, or maybe grenades.
(The trench coat with the D-ring was originally military, but after World War II, many soldiers abroad still preferred to wear the wartime trench coat.
When the army had too many trench coats in stock, the government distributed extra double-breasted waterproof jackets to the public.
That's how the military-style trench coat came into the spotlight.)
The D-ring on a man's windbreaker is a classic element to this day.