There's Hi Viz fiber optic but they adjust the same as OE sights. Next is tech-sights. They are quite nice. Ive been through so many scopes, rds and irons for my 10/22 and keep going back to the OE irons with the large square notch. I just love them and I shoot so damn well with that setup. Oh and for a simple low budget option check out Skinner sights, notably his lo pro rear sight that threads into one of the scope base threads on the receiver. He has tons of apertures from ghost ring to serious target work. Pm me if you want a brass one with .096 and .004 apertures. I could part with it.