The HS403C is a 20mm micro optical sight designed for rifle and carbine applications. Specifications for Holosun HS403C 3x28mm Micro Red Dot And HM3X Magnifier Combo Pack: Manufacturer: Holosun Color: Black Magnification: 3 x Objective Lens Diameter: 28 mm Reticle: 2 MOA Dot Illumination Type: LED Illumination Color: Green Brightness Settings: 12 Eye Relief: Unlimited Adjustment Type: MOA Adjustment Click Value: 0.5 MOA Emitter Type: Enclosed Parallax: Parallax Free Water Resistance Level: IP67 Weight: 43.9 oz Attachment Type: Picatinny Lens Type: Glass Features of Holosun HS403C 3x28mm Micro Red Dot And HM3X Magnifier Combo Pack Solar failsafe Holosun's Green Super LED with up to 50k hour battery life, and 2 MOA Dot The HM3X is an Aluminum bodied 3X magnifier that includes a quick release Ambidextrous Flip-to-side mount with Absolute and Lower 1/3 Co-witness mounting solutions IP67 certified water resistance, with windage and elevation adjustment for precision zeroing Package Contents: Holosun HS403C 3x28mm Micro Red Dot And HM3X Magnifier Combo Pack