The Olight Osight S -uper Compact Carry reflex sight features the first ever magnetic charging capability. The charging cover simply drops on top of the Osight S to charge the built-in battery whenever you need it. However, you won't need it often since the Osight S boasts almost 22,000 hours on level 3 brightness with the 2 MOA Dot reticle selected.The Osight S is a fully enclosed optic giving it protection against the elements and a disortion and parallax-free performance. This optic is great for rifle and pistols using the popular RMSc mounting footprint. FeaturesFully EnclosedMagnetic ChargingMulti-Reticle SystemRMSc FootprintOAL Proprietary Aluminum Alloy HousingLarge Viewing Window: 0.83" x 0.55"