"Not bad, but there are better options. The red dot is a little small, but you can deal with it..Constructed with all plastic, so have a sling or something to make sure it doesn't drop, because it might break. However, the red dot is clearly visible day and night which is a plus. It works great on my m4. Pros: cheap, visible day and night, extra battery comes with it Cons: all plastic, and not as high quality as more expensive optics, and a small red dot. Overall, good for the price, you get what you pay for."