I have a nice little compact one. It came in a little plastic box about the size of a box beam made out of two longitudinally folded dollar bills. (~6"x1"x1")
I think that it goes up to 21.8 ft-lb or N-m (I think one is 21.x and the other 14ish)
it would probably work well on scopes, it has a standard hex-bit drive.
I believe it is made by Gustiforza(sp?)