What you have is a 3X magnifier that can be used behind an Eotech weapons sight to provide magnification. It can be used as a small monocular.
I have one but never use it. It adds a lot of weight and for very little gain.
In my experience, the Eotech holo sights work pretty well and are not really useful when you start adding optics to them.
You may have a very different need. They are pretty expensive and built like tanks but they are also cumbersome.