Many times when in the field or during competitions you need to transition between no magnification for speed in close-range combat and magnification for precision shooting as situation dictates. The Athlon MAG31 - 3x27.5 Magnifier mounts behind a traditional red-dot sight to provide magnification when needed. The mount has the ability to swing out of the way when not in use, but can quickly be placed behind the red dot to increase the magnification for longer mid-range shots. Rugged construction. Multi-coated lenses and 30mm tube for excellent light transmission. Nitrogen purged, shockproof, waterproof, and fogproof.