Headwear with visible 'ear flaps' dangling from them.
Characteristic of Ushankas and Aviator Caps when the hat flaps are left to droop, rather than being pinned up.
It also be Hats that normally <i>don't</i> have hat flaps, but has them incorporated into their design.
For hats that have a single flap on the back of the neck, see Neck Flap.