The Micro Red Dot Optic is customized for a perfect Picatinny rail fit on your AR-15. The sight features an advanced ambient light filter with auto-dimming capabilities and an auto-shut off feature to preserve battery life. It is a one piece optic with an aluminum nitrogen-purged tube that allows for a lower 1/3 co-witness. With a 3 MOA red dot and an anti-reflective coating, youll find the Micro Red Dot to be a competitive sight to those on the market. Allen key, rubber bikini cover, AAA battery and a 1-year replacement warranty are included. If you want a durable yet affordable micro red dot sight, look no further than Black Spider Optics.