HS407K X2 RED Dot Sight - HolosunSince Holosun's inception in 2013, their main goal has always been to bring cutting edge technology to the end user. They continuously strive to improve and innovate their products by producing technology that makes sense and works! The HS407K X2 is an open reflex optical sight designed for subcompact pistol applications. The HS407K X2 improves on the previous version by adding Lock Mode which was first introduced in our 2018 LEM pistol optic models.