Not perfect but still decent - ADE Advanced Optics RD3-006x 1x Reflex Green Dot Sight w/D1 Rear Optic Mount Plate

The optic works fine overall and the blue dot is easy to see. My only complaint is that I had to spend a little extra time adjusting the brightness settings to find what worked best for me.

The build quality seems solid and it has held zero without problems. While I wouldn't call it perfect, it performs well for the price and I'd still recommend it to most buyers.