There are 2 pieces in the following part: ✔ 1st piece: Red Dot Wind with adjustable reflective holographic sight with illuminated red and green holographic sight with 4 reticule patterns. ✔ 5.4 inch Picatinny Rail Mount Adapter for Mossberg 500 and 590 Shotguns. Our Reflex Vision is one of the best fields of view in which dual red and green reticles. The red micro dot has 4 grids with red and green brightness levels (3 red and 3 green). It also has a Mil-Spec 1913 Picatinny mounting system. Material: The Reflex Sight and Picatinny rail are made of high quality 6061 aluminum with a light and solid matte black frame. Weather Conditions: The Reflex Vision is fog resistant, shockproof and waterproof. EASY TO INSTALL - The Reflex Sight and Picatinny / Weaver rail is very easy to install on the Mossberg shotgun with supplied screws and Allen keys without any modification. 1 x 12mm x 12mm Magnifying Objective Lens Unlimited eye relief. Multi-Coated Lens Specifications: ✔ Reflex Sight is compatible with the 12mm rail system. ✔ Wind and elevation adjustment. ✔ Double red and green. ✔ 6 MOA ✔ 13 slots. ✔ 5.4 inch rail length. ✔ Rail Weight: 1.4 oz. Includes: 1 reflective look. ✔ 1 x 13 Slots Picatinny Rail ✔ 2 Allen Keys (different sizes). ✔ Bolts and nuts