This backup sight from Mission First Tactical mounts onto a Mil-Std 1913 Picatinny rail and accepts any standard front sight post. A standard sight tool is required to adjust” with each click equaling 1/4 MOA. The sight folds to the rear” the correct direction in case the rifle is dropped. When folded the sight post is shrouded and protected from dust and debris. The sight has a slim profile” allowing it to sit below most optics.