Gas Mask Can Markings

[Fabe]

Hey Guys -
This gas mask can set just came to my possession, and I was wondering about the written markings inside the lid:
"F. Ba 12. 4 A
477"

The "477" is also on the mask - and just lot number, but maybe someone can encrypt the rest. Thanks in advance!

Cheers,
Fabe

[BrodieBartfast]

The first letters and numbers are unit markings. '477' would make this the 477th mask to be issued to this particular unit. I can't help with the unit markings, unfortunately.

Regards, B.B.