The Vortex Strikefire II Red (or Green) Dot optic was just what I was looking for for my new AR-15. Easy installation and only took about 15 shots at 50 yards to get it dialed in. I have been able to easily stay on target at 100 yards as well. I have other rifles for long range so this optic was exactly what I was hoping for. I have been using the green dot function but both the red and green are easy to see and allow the shooter to keep both eyes open to maintain good peripheral vision while still allowing accurate shot placement. If you are looking for an optic that allows dependable and quick target acquisition at a price that won't break the bank, the Strikefire II should serve you well.