For what it does, it's great. - TRYBE Optics Enhancer Scope Magnification Doubler w/ Tube Mount

This enhancer will double your magnification.
The optics clarity is as good as the original glass.
The field of view and eye box both become smaller, but that is unavoidable when you add magnification.
The two cons you need to know about.
One huge pro is the magnifyer has to be zeroed. I zeroed mine to 4 inches high at 100 yards, which gets me close at 300.
1. The alingment marks on mine when centered ate not tight enough and would loosen. I had to tighten to where the magnifyers marks is on the edge of the adapters mark. Not a big dea
2. Your reticles BDC marks are halved.