Detachable O2 mask above 10,000' AGL or during some simulated emergencies.
Boom mic with adjustable swivel all other times.
SV-2 Survival vest & Parachute.
Helmet with visor, flight suit, gloves, flight boots, kneeboard, and dog tags. Most people also wear ear plugs to drown out the background noise.
95% of the flight time is without the O2 mask on. It's is connected to the O2 supply, but you don't wear it very often.