The Midas MG31 by Athlon Optics was designed to provide shooters with the ability to quickly transition between magnified and non-magnified shooting. The MG31 mounts behind a standard red dot sight, swings out of the way when not in use, but can rapidly be deployed to provide your red dot sight 3x magnification for mid to long range shots. This magnifier is well suited for use on modern sporting rifles and is perfect for use in the field or in competitions. Features of the Athlon Optics Midas MG31:Enables quick transition between magnified and non-magnified aiming For use with red dot sights 3x magnification Waterproof, fog-proof, recoil proof Athlon Midas MAG31 - 3x27.5mm Magnifier 403030