Mounting ring specifically designed for the Cross-Eye Periscope, but could also be used to mount other 34 mm diameter light duty accessories.  Constructed of durable glass-filled nylon.
The single thumb screw makes it easy to mount on any 1913 Picatinny rail system.  Simply remove the thumb screw to open the ring and close around the Cross-Eye Periscope.  Place on the rail behind your sighting system and replace the thumb screw.  Adjust the Cross-Eye Periscope angle for natural sight alignment and hand tighten until no wobble is felt on the rail