AIRSOFT SRS REPRO. NOT A REAL SIGHT, REPLICA MADE FOR AIRSOFT. FREE 7-14 DAY SHIPPING IN THE U.S The SRS is a highly engineered sealed reflex sight that eliminates the tube-effect typically associated with other sealed reflex-style sights. The modern design incorporates a 28mm aperture that allows easier target acquisition. Its 1.75 MOA dot is small enough for precision and bright enough for speed. Specification: Manually Adjustable Brightness Controls Compact Snag Free Design Military Grade Aluminum Alloy Housing Multi-Layer Broadband Anti-Reflective Coating One (1) AA Alkaline or Lithium Battery