Where made: 
15 × 8.5 × 15 cm

The prismatic binocular uses two convex lenses, one for objective, one for eyepiece. This lens system inverts, and produces a mirror image of, reality. The prismatic system corrects for this. The light goes thru a convex objective lens, is reversed right to left thru the first internal reflecting Porro prism, is inverted thru the second Porro prism, is viewed by the convex eyepiece lens, to be viewed in the same orientation as the naked eye.