Small stereo tube 10*25 manufactured by the Obukhov plant, 1915, in the original trunk.

A very rare pipe in excellent condition. About 2500 pieces were made in total. Currently, only 2 MCTs from this manufacturer are known, only this one is in the original trunk. The history of the birth of this optical device dates back to the period 1893-1894, when the company of K. Zeiss in Jena received patent No. 77086 dated July 9, 1893 for this invention. The "binoculars for observation from behind cover" were soon appreciated by the military and were ordered for the German and British armies. The first batch was probably made in 1897 and underwent a "baptism of fire" in 1900-1901 as part of the British army in combat operations in South Africa. RIA's small stereo pipes were obviously supplied by K. Zeiss's company in the period 1904-1905, when K. Zeiss's branch office Zeiss in In St. Petersburg, 201 stereo tubes, previously intended for the German army, were redesigned to meet the requirements of RIA. This information is contained in the book "Binoculars and Spotting Tubes" by the German researcher of the history of optics Hans Seeger.

In the Military Historical Museum of Artillery, Engineering Troops and Signal Troops of the Ministry of Defense of the Russian Federation in S.-In Yekaterinburg, the MST is stored in the section of the Russian-Japanese War with the Obukhov plant marking, which indirectly confirms this version. Subsequently, the production (apparently under license) of the MCT was mastered by the Optical Workshop of the Obukhov Plant with some changes, primarily affecting the fixing unit for the position of the pipes and the handle. Later (on the 1915 models), the design of the hinge assembly of the periscope tubes was also changed – from a separate unit made of brass (as on the first Zeiss models), it (more precisely, the arcs securing it) was made of aluminum alloy directly as an element of the body (in the company of K. Zeiss, such a modification was conducted in 1907). During the same period, apparently, the design of the locking unit and the design of the handle itself were changed once again (for a number of reasons). This assumption needs to be further verified, since the only copy of the MST produced in 1915 does not have a handle. The body of the MCT is made of aluminum alloy, covered with black artificial leather. Two periscope tubes (a modified Porro – 2 prism system) are connected by a hinge with the possibility of fixing the position of the tubes using a special latch (clamp) made in the form of a "wing nut" (in 1915, the design was apparently changed).The device is equipped with a wooden handle (in 1915, the handle may have been replaced with a metal one of a different shape) for ease of use and for the possibility of installing the MCT in a stationary position. In the field of view of the right eyepiece there is an engraved grid of the "Russian type" in the form of a "cross". The fastening mechanism of the grid allows you to change its position relative to the horizon. The prisms of the lenses are protected in non-working position by special rotating cylindrical shutters. The case of the device is made of yellow (light brown) leather, has two German-type rotating hinges for attaching the shoulder strap and a wide leather loop for attaching the case to the waist belt, light filters and a spare eyecup are fixed under the cover of the case, as well as a pressure pad for fixing the position of the device in the case.