Airsoft Armoury does a quick review on three optics from Vortex covering the Vortex Venom, Crossfire II 1-4x and Crossfire II 3-9x... "Vortex is for the airsofter who wants to pay a little more to get so much more! Here are three examples of three very different aiming devices designed for, among other things, airsoft. The sights are also particularly suitable for GBB/GBBR, as they can withstand the resistance from the recoil of the GBB/GBBR."