The Ultraoptec S 4x32 AO is a fixed 4x magnification riflescope with a 32 mm objective lens. AO stands for adjustable objective: the ring on the front of the scope lets you adjust the parallax for the distance you are shooting at, which keeps the reticle on target when your eye position moves, important for accurate shooting at shorter and varied ranges, for example with an air rifle or rimfire. We could not confirm the tube diameter, reticle type or mounts for this model, so please check the packaging before buying.