Hellqvist and Pramm Diopters
I think the Hellqvist must be a nice alternative to a traditional diopter sight for someone who like to keep the traditional look on his rifle. It is sooo small when seen next to a normal diopter sight. The Pramm in the picture, is a post 1953 model according to this post. The difference is an added side locking screw. The Pramm was constructed by Otto Pramm and introduced to the public in 1945. I have an early style Pramm clamp on front sight tunnel as well, for use with this sight.