AKA the *Ridgeway Cap,* *coffee can* or *Fidel hat*. It was a *desired* substitute headgear before the adoption of the OD green baseball cap in the early 1960s, and was universally detested because it could not be easily carried rolled up or stuck in the trousers belt when indoors, where uniform caps/hats are not worn.
They were reportedly adopted after former Army Chief of Staff Matthew Ridgeway's wife commented to her hubby during a parade about the troops wearing hats like gas station attendents. Happily they fell out of favour in the early 1960s after Fidel Castro began wearing a heavily-starched Soviet-bloc equivalent as his trademark, though he was known to frequently sport a beret about as often.
The winter version was a foldable soft cap equipped with fold-down/fold up earflaps, very similar to the current issue winter *patrol cap*. And it could at least be worn with radio earphones on while on radio watch, a serious consideration for those of us in radio-equipped vehicles.
