The Telegraph Key that Won the War
The J-37 Morse key ... During WWII, the Korean War, and even into the Vietnam era the U. S. Signal Corps designated many of their Morse keys with a "J-" and a number. The real workhorse key during those years was the J-37 "Mae West" key. There are many more glamorous wartime keys around, but the keys that carried the bulk of the action were the J-37 keys. The J-37 key is unusual because, with the addition of different bases and connections, it became part of other more special purpose keys.
I found this one at a yard sale for ten bucks.