New reproduction khaki officer's crusher style cap as issued to officer's for summer service uniform during WWII. Crushers were first made popular by pilot's when they removed the metal band stiffener to easily facilitate the wearing of head phones but eventually became stylish.Feb 18, 2010 Here's a typical EM cap. Notice the lack of a mohair band. Here's an Officer's cap, with mohair band. Many service caps eventually wore a 50-mission crush due to the removal of the stiffener, while a true crusher was designed to be rolled up and stuffed in.