MTek FAST T3C
MTek Weapon Systems is the manufacturer of mandibular ballistic protection for real world applications, but they've shown some love for milsim/airsoft and have adapted one of their offerings (the FAST G3C) into a milsim/training product named the FAST T3C. Check out a review of it by Dr. Airsoft below:
Now if only more companies would jump on this bandwagon. I think many products would be easily adapted to milsim paintball/airsoft offerings, and branded companies could prevent 3rd party pirating manufacturers from ripping off their ideas by simply creating the product first.