The HS510C Open Reflex Circle Dot Sight has an open frame for a wide sight picture. 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, a 2 MOA dot only, or a 65 MOA ring only at the push of a button. Better yet, the same LED projects both reticles, so no re-zeroing is necessary.