My first firearm was a Glock 17 MOS and I took it multiple times to plate shoot competitions (at 15 yards) but I was shooting horribly with it so I put it away for a few months and was using a Tangfolio Witness Elite Match which I love and I can shoot well with it. I decided to take advantage of the MOS feature of my Glock 17 and I purchased this Vortex Venom red dot. I never shot using a red dot before so I took it to the range and used about 100 rounds to zero it first at 7 then 15 and finally at 25 yards. During the range session, I noticed that the groups were very tight at 15 yards so I decided to take it to the next plate shoot night which happened to be "Low light shooting" night. I was amazed my self at the accuracy and consistency of this targeting system. Not only I won the competition but did it undefeated and I owe it all to this red dot. I shot about 100 rounds during the competition and the zero held perfectly. Needless to say that the Glock 17 MOS with the Vortex Venom is my favorite firearm for plate shoot competition and I am going to try it for USPSA next time.Features include auto shut off (after many hours) and auto brightness of the red dot depending on the ambient light but you can also adjust the brightness from the Up/Down arrows on the side. The total height of the sight feels very low compared to some other red dots I have seen. Yet, during targeting it is very easy to see the target through the glass. Only drawback is that when I first bring the firearm up to firing position, sometimes I struggle to find the dot. Perhaps a co-witness front sight would guide me as to if I am aiming to high, too low, left or right while I am looking for the dot but when you shoot with a dot, the focus should be on the target and I am afraid that a co-witness front sight would bring my focus to it out of a habit so I am planning to use it as is for a while to see if I can start finding the dot easier.To obtain the correct screws for the Glock 17 MOS, I called Vortex at eight hundred 426-0048 x4 and I got to speak with a person immediately. I told her that I ordered the Vortex Venom and I need the screws to mount it on the Glock. She asked for my name and address and 2 days later the screws arrived in an envelope free of charge. I also attached some photos that show how to install it on a Glock 17 MOS.Overall, with great service, lifetime warranty and the same quality with red dots that cost twice as much, I believe that I got the most value from this purchase than any other accessory I have purchased do far.███ Update 8/31/2017 - I have been using this for almost every competition I enter now and I have shot over 1000 rounds with it. Zero is still holding and did not have to adjust it since I first zeroed it. At this point I feel very confident that the hit will be where the dot is and all I have to do is make sure that the dot is on the target. ██████ UPDATE 4/16/2018 - Since this review, I purchased one more and installed it on my Tanfoglio Witness Elite Match 22lr conversion kit. I mounted this one using a plate from EGW and it has been working great. In the meantime I moved the once I had on my G17 to my G34 so I can use my G17 for IDPA practice with iron sights. Moving it from one Glock to the other (both are Gen 4 MOS) required no adjustment and the dot was spot on. As a matter of fact, I have not touched the adjustment screws since I first sighted it. Battery life has been fantastic, I turn it on during competitions and do not shut it off until we pack up and leave. The dot is still as bright as the first day. I have also used it in USPSA style competitions and during day time, I have no problem seeing the dot. I never do any adjustments to the brightness because the the auto brightness feature works great for both low light and day time (sunny). Just turn it on when I get there and off when done. ███