This listing is for a Selsi 50X Periscope Made in Japan. I don't know what this is used for, any info is appreciated and I will post it at this listing.

"A periscope is an optical instrument that uses a system of prisms, lenses or mirrors to reflect images through a tube, optical instrument used in land and sea warfare, submarine navigation, and elsewhere to enable an observer to see his surroundings while remaining under cover, behind armor, or submerged".

Measurements:

• Length: 4 1/8"
• Diameter: 5/8"

Please view pictures for details.