What is this scope ~?~?~?~?~

[pred]

Again I found myself at a flea market and today was military day, There was one thing I found that interested me and it was this scope. It weighs in at 3 lbs, The big end has a coil spring built in, and will compress about 1.5". and the eye relief is pretty much with your eye against the bug end cup. Both ends have rubber cups and if you look closely, There is a small lense on the wider strap on the scope, and if you illuminate it you will see what I got a pic of in the 3rd picture.\
The entire length is 16",,, And I dont know anything more about it, I can only find one area with markings pictured in the second pic.
What is it and what did it belong to?
I paid $40 bucks for it just because I thought it was pretty cool, But that's all I know...
Any ideas?
Thanks for any possible info!
Peter

This last pic was shining a bright light in the lense on the strap at night to show what lights up, It can be seen in daytime, But cant capture it till dark with my little camera.

WHAT IS IT?

 

[Crazy K38]

its a pak scope (pak 40) and was also used on most of the 2 cm flak guns,
all variants look the same on the outside, only the reticle (inside the scope) changes
a list of all the scopes of german WWII vehicle mounted weapons can be seen here, viewtopic.php?t=69949&highlight=optics with some pics for cross-reference hope it helps.