This BSA Multi-Purpose Sighting System is a wonderful light weight sight for close quarter and medium range targets. Light enough for small calibers plinking on the range, yet durable enough for larger calibers used by hunters and law enforcement departments.The sight features a red, green and blue 5 MOA dot that is adjustable via the 11-position rheostat and powered by a 3 V CR2032 battery. The integral mount will fit both 3/8 and 5/8 inches weaver-style rails. Features: Multicoated lens coating 50 yd parallax setting Unlimited eye relief Waterproof, shockproof, fogproof 5 brightness settings Limited 1 year warranty