Amazon.com : Sightmark Ultra Shot Reflex Sight : Paintball Sights : Sports & Outdoors My step son turned me onto the above sight several months back. A number of his fellow LEO's have purchased them and around here they are known as "The Poor man's EOtech". I ordered the first 2 and mounted then on a pair of m4 kits that I built up for a friend. Out of the box the unit feels well built. Has a bit of heft, just feels good. After installing the battery I mounted the unit to the upper using the supplied allen wrench that is also used to adjust the windage and elevation. Turning the unit on you have a choice of five intensity settings, and four reticle choices. Reticle color is RED. Indoors I did notice a bit of distortion when used on the higher settings. Outdoors it wasn't nearly as noticeable. I found that I liked the sight best on the #2 or#3 setting, and at these settings the sight picture was sharp on all of the different reticle settings. It has a good FOV and presents to the eye very well. Both of the weapons these were mounted on are flat tops with no backup sights so they were mounted directly to the receiver. They can be used with spacers to co witness with back up sight systems. Adjusting the sight is easy, but can be a bit frustrating for someone not used to the sighting in process,mainly because there isn't any 'clicks'. You do not know how far you've moved your setting until you fire the weapon after the adjustment. This wasn't a big deal for me, but I can see how it might be for some folks. I have now installed 12 of these sights on different AR type platforms and the most rounds fired to sight one in was 12, with the least being 6.The average being 9.(I use 3 shot groups per) I have had very good luck with return zero after removing and reattaching the sight. A couple of them were off approx. 1" from the original zero. These sights appear to hold their zero well after a thousand rounds fired semi auto, and roughly 600 on full auto/3 shot burst. They are not billed as waterproof, but I have taken one out during a downpour and fired 100 rounds with no issues. The sight comes with instructions, battery,soft cloth for cleaning and a neoprene type cover. Sightmark also offers a 3x multiplier that will mate up with this sight for those who may want one although myself I've never been a fan of any multiplier. Based on my experience thus far I highly recommend this sight, especially for those budget minded folks. Is it an EOtech? Nope, and one shouldn't expect it to be for 80 bucks. But for 80 bucks I challenge you to find a better reflex sight. Amazon.com: Sightmark Ultra Shot Z-Series Reflex Sight: Sports & Outdoors The above is basically the same sight as the first except it has a quick release mount and the reticles are GREEN.