The HS403R is a 20mm micro sight designed for rifle and carbine applications. HS403R features a Rotary switch to select reticle intensity, Holosun’s Red Super LED with 50k hour battery life, and a 2MOA dot with 10 daylight and 2 night vision compatible reticle intensity settings. HS403R housing is made from durable cast aluminum and includes both a lower 1/3 co-witness mount (1.63â€) and a low mount (.75â€) for low-comb height rifle applications.  Additional features include rubber lens covers, and a battery compartment integrated into the Rotary switch for the 2032 battery. HS403R is a versatile sight for users of all levels.  In the Box Lower 1/3 Cowitness Mount Low Profile Mount T10 L Key Rubber Cover User Manual CR2032 Battery Lens Cloth  OPTICAL SPECS Reticle 2 MOA Dot Light Wavelength 650nm Reticle Color Red Parallax Free Yes Unlimited Eye Relief Yes Magnification 1x Multi-Coatings Yes ELECTRONIC SPECS Power Source Battery Battery Type CR2032 Battery Life (Hours) 100000 Brightness Setting 10 DL&2 NV PHYSICAL SPECS Window Size 20mm Diameter Dimension (in) 2.75×1.43×1.62 Weight (oz) 3.53 MECHANICAL SPECS Housing Material Durable Aluminum Surface Finish MAO Adjustment per Click 0.5 MOA W&E Travel Range ±50 MOA ENVIRONMENT SPECS Storage Temperature -40℃~70℃ Working Temperature -30℃~60℃ Submersion IP67 Vibration 1000G