I have this sight mounted on my Echo 1 MK36C. It has an easily adjustable knob for the brigtness. Red seems to be better for day and green for night (or who knows...might just be me). It is a bit tricky to mount with the removable rail clamps, but it gets on pretty easily and stays in place once you crank down the knobs. Mine took a bit of work to get zeroed (for some reason it was way up and to the right), but I got it shooting dead center after about 15 minutes of messing with it. The elevation and windage knobs are a bit of a pain to adjust but if you have a flat-head screwdriver you should be good. Overall a solid sight.
Red AND Green dot
Stays on rail tightly
Rail clamps are a bit annoying to get locked down
Didn't come zeroed
Elevation and windage knobs require a screwdriver
Rating: [4 of 5 Stars!]