Can't really tell what it is. Upper left is a Notrh reference, upper is hand level, a 3 legged tripod with some kind of instrument not a transit and the intrument person looks a little wierd, the rod person is holding some type of reflector. It could be some type of Electronic distance measuring systems (EDM) cover. It is not any that I have seen before. Distance finder printed on the face is not a term that US surveyors use. EDM is the term used for distance measuring lasers. I don't know what it is. Looks interesting. Great find.