Actually that is an early Litton or Laser Systems hand-held laser range finder. (I don’t know what model; Mk 1, 2, 3, etc). Accurately reads distances in meters out to a few kilometers, probably for use with that 50 BMG M88 “anti-material rifle”. I’ve read that it’s mil-spec laser is very strong (dangerous). Here’s a newer version of what’s in that picture:There is some kind of fancy camera all the way to the left in the picture
…Cutting edge back in 1991. Random fyi.