J-37 Hand Key
Countless number of these hand keys were made and used by the military.
JJ38 Hand Key
They are still very popular today with Amateur Radio Operators..
Flameproof U.S Coast guard
This key is new in the box with the Coast Guards orange stamp on the bottom. Many companies made these keys for the different branches of the service, this one was Mfg. by Molded Insulation Company Phila, PA. and stamped CMI 26003A on the base
This hand key came from a WWI Army set. The knob goes up, and the mechanism then is upside down from that of a normal key. The mechanism is normally hidden, except the whole thing hinges up to access the adjustments. According to Larry Nutting K7KSW author of the Military J-Series Telegraph key book, it is quite rare!
WWII era British Army Handkey
Top : KEY.W.T. 8 AMP, NO 2 MK III
Bottom : ZA 28685
Navy WW-2 Semaphore Blinker Key