Vortex SPARC AR Red Dot Scope Simple€”Fast€”Effective€”Point and Shoot. When you boil it down, those are the advantages of a red dot sight. And thats what the SPARC AR delivers - all in a durable, lightweight, compact, and ultra-clean package. Digital rear-facing controls for power and dot brightness offer quick access and are viewable from the shooting position. 2 MOA dot diameter promotes precise point of aim. Automatically returns to last dot intensity used when powered up. Unlimited eye relief and parallax free, the SPARC AR gets shooters on target fast. Waterproof, fogproof and shockproof for ultimate durability. Unit automatically shuts off after 12 hours to prevent accidental battery rundown and operates using a common AAA battery. Duty rifle - home defense€”recreation, the SPARC AR is built to handle all your red dot needs. Features: Fully Multi-Coated Multiple anti-reflective coatings on all air-to-glass surfaces increase light transmission Bright Red Dot Display is highly visible in daylight Brightness Settings Provides 10 variable illumination settings€”the lowest two settings are night-vision compatible Parallax Free All red dot and holographic sights will exhibit some small amount of parallax. Matching current industry practice, this small amount would be considered parallax free and will make a negligible difference in the SPARC ARs performance Nitrogen Gas Nitrogen gas purging with o-rings-seals delivers fogproof, waterproof performance Single-Piece Chassis Compact and lightweight Waterproof O-ring seals prevent moisture, dust and debris from penetrating for reliable performance in all environments Shockproof Rugged construction withstands recoil and impact Hard Anodized Finish Highly durable low-glare matte finish Operating Temperature Rated from -4 degrees to +158 degrees Fahrenheit Multi-Height Mount System Includes a spacer shim that can be utilized to provide two different mounting heights: lower 1/3 co-witness (40 mm) & absolute co-witness (37 mm) Unlimited Eye Relief Non-critical eye relief for rapid target acquisition Battery Life 12-hour auto-shutdown feature maximizes battery life. Typical battery life is 300 hours at maximum brightness and 5,000 hours at minimum brightness setting.