11/20 Mm holographic sightThe product is shipped based on the color or size of the main image of the product page.main characteristics:-Built by aluminum alloy with matte black anodized treatment.-weight lightweight and compact design, waterproof and shockproof.-Anti-Glare reflective coated lenses that gives good optical clarity.Tubeless-design with openings 22x33mm SLR lens provides a wide field of view.-a 3-position dimmer control (Red and Green).-installed 4 different reticles (Dot Circle, Cross, 10 and 3 MOA MOA) for maximum versatility.-vis head drift type and click in elevation adjustments, with locking screw.-with integrated 20mm rail mounting bracket.-adapted for rapid firing or shooting of moving targets besides normal shooting.-Powered by 1 x CR2032 lithium batteryGoal Goal Dimension: 33mmProduct Color: Blacklength: 8.5 cmProduct dimensions (W x D x H): 8.50x4.00x5.50 cm / 3.35x1.57x2.17 inchNotes:1. Please allow 1-2CM differs due to manual measurement.2. Real color may slightly different from pictures due to computer screen's resolution, brightness, contrast etc. Hope understanding. Have a nice shopping dayNote:Looking directly at the sun through this sight may cause permanent eye damage