Hensoldt-Wetzlar optical device

I don't know what this is. If you can tell me what it is so I can assess the value, we can come to a deal. Exchange for money or trade. Difficult to say for what, because I don't know the value. If you are interested just message me and we can work it out.

It is 1 3/8 inches long. It has a very small lens that can be looked through and a rotating disk of different aperture sizes. Says Hensoldt-Wetzlar on it. I can see that the company made binoculars but I don't know what this is.