Very easy to mount and to set up - AIM Sports 1x33 Dual Illuminated Red/Green Reflex Sight w/ 4 Dot Reticle

You can’t go wrong with this reflex sight optics planet has the lowest prices online..I mounted this sight on my 7.5” pistol length .300 blackout. I found it very easy to mount on my rail and to sight in with a few clicks on the adjustment screws I was zeroed in no time. Has several options on cross hairs and you have the option of changing the retical color to green or red.