I ran across this crystal the other day in some military stuff...Does anyone know what it might fit...

It's a time of trip dial. The hands would be set to the time of take off. As the clock continues to go forward you can see how long you have been in the air. I don't know which clock it came from, I looked at a few RAF clocks but they had different time of trip hands from yours.

Greg is correct, as always, in how it is used, but I am not able to say that it is either military or of any particular age. These have been used for a very long time on both military and civilian aircraft clocks.

Here is an example of a brand new electrically powered, civilian aircraft clock that you can buy for your aircraft's instrument panel today that has one of these elapsed time hands crystals. Unless there is a part number on yours it would be pretty much impossible to say whether it is from the 1940s, 50s, 60s, all the way up to yesterday, and whether it was sold to a military or civilian buyer who wanted to add this feature to their aircraft clock.

Thanks Greg and Jim..there is a hand written WC number on the box it was in...I think it was WC 1000 but not 100% sure..I will check later on tonight..Thanks again...Gary

That was it...WC 1000...

Sorry, but I do not know what WC 1000 might mean other than perhaps a manufacturer's code - perhaps something like Watch Crystal Model 1000 or such???

Thanks anyway Jim...