JAPANESE MILITARY TELESCOPE

This is another optic out of my collection don't remember when I purchased it so it was a while ago. I do not know what this optic was used for but its a well built item and heavy. The case is complete with a makers tag on the front with number 244 on it and there are heavy carrying drop down handles Inside the box the top has two Japanese labels covered in clear plastic and a long cleaning brush with paper around the bristles secured in the top retaining section. The telescope is 19" long with a brass shell and end caps. The rear cap is maker marked and listing 6 x 8'20". The lenses has a cross hair targeting cross and the end cap for the telescope. The eye relief is adjustable and the rubber has mostly rotted away. The lower case has a compartment that sunshades and four replacement light bulbs. The second compartment has two replacement eye pads for the scope. The third compartment has what appears to be a twist on cap for something and the fourth compartment appears to be a screwdriver with a hollow handle, the handle has a lot of Japanese writing on it.The bottom of the box is chalk marked 244 to match the scope.The bottom of the case has all the little pieces of rubber from the eyepiece it has not been cleaned for many years before I got the set. Condition Very Good +++ ANYONE WHO CAN TELL ME EXACTLY WHAT IT WAS USED FOR WOULD BE APPRECIATED.