A single variant sort was known as "trench binoculars", a combination of binoculars and periscope, typically useful for artillery spotting reasons. It projected just a few inches higher than the parapet, thus trying to keep the viewer's head properly during the trench. Provided the method was these a good a https://canon-cameras97530.ampedpages.com/rumored-buzz-on-canon-cameras-45479866