Holosun 503R The HS503R is a small compact micro red dot optic that features Holosun s new Rheostat Dial to adjust brightness settings. Employing our LED technology, The HS503R can achieve constant on battery life of up to 100,000 hours on medium setting. This optic features Holosun s proprietary Multi-reticle System (MRS) giving the user 2 reticles to choose from. New rotary control for faster operation and visual brightness indicator Advanced technology LED allows up to 100,000 hours of operation on one CR2032 battery Unlimited field of view Parallax-free with unlimited eye relief Durable and reliable construction Low mount and 1/3 Co-witness mount included OPTICAL DATA Light Source LED Reticle 2MOA Dot & 65MOA Ring Parallax Free Yes Unlimited Eye Relief Yes Magnification 1x Multi-Coatings Yes Integrated Laser No ELECTRONIC DATA Battery Type CR2032 Battery Life Up to 100,000 Hours Brightness Setting 10 Daylight & 2 NV Compatible MECHANICAL DATA Housing Material Aluminum Surface Finish MAO Housing Color Black Adjustment per Click 0.5 MOA W&E Travel Range 50 MOA Storage Temperature -40 - 158 Working Temperature -22 - 140 Submersion IP67 Vibration Up to 1000G PHYSICAL DATA Window Size 20mm Diameter Dimension (in) 2.75x1.43x1.62 Weight (oz) 3.74 Central Height (in) 1.63 Due to shipping restrictions batteries are not included. This product is covered by HOLOSUN Limited Lifetime Warranty