The HS507C X2 is an open reflex optical sight designed for full-sized pistol applications. The HS507C X2 improves on previous versions 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, Solar Failsafe, Multi-Reticle System, and Shake Awake. The durable housing is made from 7075 Aluminum, uses an industry standard footprint, and houses the 1632 battery in a side-mounted tray for easy replacement when needed.