USA Pressure Firing Device M1A1 from what i have found is a mechanical device used for firing explosive charges it can be fitted mines ,hand grenades, bangalore torpedos and no doubt plenty more ,it comes with a variety of extensions for the pressure head.
Operating pressure is 20lbs
My example has no visible markings
feel free to add more images and information to this post
Operating pressure is 20lbs
My example has no visible markings
feel free to add more images and information to this post