First off, I was very happy with DP's quick delivery. This is my second night sight from Warren. Clear sight in the dark. I used this for my Glock 30 for home defense. Sight alignment was perfect when tested in the range from 5 - 25 yards. I only gave this sight a 4 star because I had a hard time installing it. The oval base on the sight had a very tight fit in the front sight hole on my slide. I had to hammer the sight in just enough to leave maybe a 0.005 - 0.010 inch gap between the bottom of the sight and the slide top. I was very careful while hammering and stop at a certain gap because I might damage the tritium insert. In spite of the gap, sight alignment was still good.