Great value - Cyelee Optics CAT0-G 1x22x16mm Reflex Red Dot Sight

As described it has all the features you want at an affordable price. The brightness goes from basically invisible to way too bright. If you have astigmatism such as myself the dot is pretty blurry on brighter settings especially compared to a prism sight. It comes with a plethora of screws of both metric and standard thread pitches and lengths. It also really well packaged and comes with the allen key/torx bits, a sticker and even a velocro/iron on patch.