This Primary Arms red dot sight is part of the SLx optics line. SLx optics built their reputation for innovation, reliability, and value. All SLx optics undergo rigorous field-testing during development to best serve you in any environment. The Primary Arms SLx MD-25 Gen 2 Microdot now comes with AutoLive, improving the functionality of an already amazing red dot sight. Stretch that already insanely long battery life even further and remove that fear of picking up your rifle and the dot not being there. With this red dot sight, the moment you pick up your rifle, the dot will turn on and be ready precisely when you need it. After sitting motionless for a brief period of time, the red dot will shut off and conserve battery. Still featuring the same lightweight and durable design with a field of view that rivals larger 30mm red dots, the MD-25 Gen 2 is a no-brainer upgrade to add to your collection.