Spuhr Aimpoint M4 Ballistic Adjustable Mount .223/ 5.56 50/ 200 to 800 meters Black. It comes standard with settings for either 5.56 or 7.62 is fully ambidextrous and can be read and adjusted from either side. As the integral Aimpoint twist mount moves parallel with the sight the Aimpoint dot will always be centered in the magnifier or NV device that is attached. For use in low light the 50/200 meter setting has one afterglowing dot to quickly and easily show the user that the sight is correctly adjusted. The ambidextrous knob on the BAM has a visible and fellable tongue so that the user knows when the tongue is in its rearward position. At the 50/200 meter setting the ballistic curves are the same so when the gun is zeroed at 50 meters its also zeroed at 200 meters with that setting. This is for control purposes as its not always possible to get access to long shooting ranges. The BAM works equally well for rifles and machine guns. Specifications for Spuhr 5.56/.223 Aimpoint M4 Ballistic Adjustable Mount: Manufacturer: Spuhr Color: Black Fit: Aimpoint M4 Red Dot Sights-Footprint: Not Applicable Optic Cut: Not Applicable Projectile Caliber: .223 Caliber Caliber: .223 Remington Package Contents: Spuhr 5.56/.223 Aimpoint M4 Ballistic Adjustable Mount Spuhr SM-101QD-2: Aimpoint M4 Ballistic Adjustable Mount .223/ 5.56 50/ 200 to 800 meters Black