Yale 7100F Series Latch Assembly
This Yale Latch Assembly is used on fire rated panic devices. A fire rated panic is a device were you can not lock the latch in the open position. It is used on doors were the engineers want the door to latch every time it closes to contain a fire. Your panic device would not have the ability to be locked open with a hex key.
Yale Part # 60-7000-0425-048