The H510C Reflex Sight has an open frame for a wide sight picture. Always on, it is powered by solar cell under normal usage, and a back-up battery to supplement power requirements in low light conditions. The reticle can be switched between a 65 MOA circle with 2 MOA dot, or a 2 MOA dot only at the push of a button. Better yet, the same LED projects both reticles, so no re-zeroing is necessary. FeaturesWhen focusing on the target, the size of the reticle will change based on the distance between your eyes and objective lensParallax free optical design, with unlimited eye reliefMinimized obstruction of vision with push button controls and a streamlined housing designSwitchable circle/dot and red dot reticlesAlways on unless manually turned offSolar cell and high capacity battery provide dual power suppliesAbsolute cowitness QD mount