The HM3X is an aluminum bodied 3X magnifier designed for use in conjunction with a red dot sight.Holosun includes a spacer with the HM3X that provides compatibility with absolute and lower 1/3 co-witness dot heights for maximum compatibility. Product Features Quick release Ambidextrous Flip-to-side Picatinny rail mount Windage and elevation adjustments Product Specifications Eye Relief: 70mm IP67 Certified Water Resistant Dimensions (in) : 4 x 1.7 x 2.5 Weight (oz) : 9.8 Housing Material : Durable Aluminum Surface Finish: MAO Field Of View : 7 degree Exit Pupil : 7.6 mm Magnification : 3X