11/20 mm holographic sight

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 battery      Goal Goal Dimension: 33mm   Product Color: Black   length: 8.5 cm     Product dimensions (W x D x H): 8.50x4.00x5.50 cm / 3.35x1.57x2.17 inch       Notes:  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 day!  Note: Looking directly at the sun through this sight may cause permanent eye damage