54, I tried the sight you are asking about and it didn't work for me. I have tried many things, Merit system, electrical tape, etc.. The Merit ring and the like work great but that suction cup blocking my vision for everything but actually shooting was too annoying, just as the electrical tape on my lens was too, I just couldn't get use to them. I bought a pair of those flip up sun glasses, drilled 3/8" hole in the lens at my sight line, covered the hole with a piece of electrical tape and burned a pin hole in it, now After a shot I just flip it up and I have clear view of what I'm doing and it works great for hunting too. Every one is different and you will have to experiment with hole size, but it works for me. Mounting a peep on the tang works well too, though much more intrusive. I hope this helps, and best of luck in your search!! If you find something new, please share it.
Robby