NCStar Red Dot for lower red dot

Here is what I have:

I have box and all manuals, paperwork that came with it. It was fired for... 20 rounds.


What I'm looking for is one that's a little lower profile. Basically dot being lower towards center of barrel.

Something similar to:

Notice that it's allen screws on the side. I can't deal with huge knobs.
I would really prefer one with a circle pattern, as this is all for quick acqusition of a target.