The HS515CU is a new micro red dot optic. The operator can switch from a 2 MOA dot to a 65 MOA circle dot with a push of a button. Our highly efficient light emitting diodes and solar panels allow Holosun solar optics to run without a battery in many lighting conditions. Additionally, the back-up battery lasts up to 5-years on the dot and up to 2 years on the circle dot. The U signifies a housing design that shrouds the windage and elevation turrets on two sides. This product includes flip-up lens covers, a quick release mount and a kill flash filter. Features; Parallax free with unlimited eye relief; New advanced technology LED allows up to 50,000 hours of operation on one CR2032 battery; 2 MOA dot and a 65 MOA ring; Parallax-free with unlimited eye relief; Powered by both battery and solar; Includes Flip-up lens covers and Kill Flash; Quick Detach 2 piece mount included.