This range finder is a superimposed image vertical base instrument designed for use with machine gun and mortar fire. It consists of two major assemblies: the elbow, and the diaspirometer unit and head. The elbow housing is of seamless aluminum, 4 3/4 inches in length. It contains the eye and field lens, an amici prism, a reticle, a penta prism, and the objective lens. The brass diaspirometer unit contains two wedges with connecting gears that govern the aluminum range drum; the extension tube made of seamless aluminum which maintains the base length of the instrument; and the cast aluminum head which houses a penta prism and a weak correction wedge.
The instrument is used in conjunction with a mount and tripod. Because of the short base length, this range finder is not accurate at distant ranges.
SPECIFICATIONS
| Power | 4 diameters | |
| Field of view (upper field) | 11° | |
| (lower field) | 4° | |
| Base length | 40 cm | |
| Measuring limits | 30 to 1,500 meters |
Japanese: p. 179 (March 1, 1945)