HOLOSUN HS507K X2 Open Reflex Optical SightThe HS507K X2 is an open reflex optical sight designed for subcompact pistol applications. The HS507K X2 improves on the previous version by adding Lock Mode which was first introduced in our 2018 LEM pistol optic models. Lock Mode, when activated, locks the buttons preventing inadvertent setting changes. Additional features include Holosuns Red Super LED with up to 50k hour battery life, Multi Reticle System, and Shake Awake. The durable housing is