The SIG Sauer Romeo-MSR Red Dot Sight is highly versatile and compatible with a wide variety of firearms including the MSR, carbines, shotguns, and even air rifles. It is a fully sealed design made from aluminum making this an extremely durable option for any use case. The protected emitter projects a 2 MOA red dot for quick and precise shooting. The top mounted rotary dial allows you to quickly switch between 10 different brightness settings and 2 night vision settings. The battery compartment is also located in the rotary knob for easy access and runs for about 20,000 hours on a CR1632 battery. The lenses are fully coated for optimal light transmission and clarity and like most red dots has unlimited eye relief and zero parallax. Additionally, it comes with see through flip up lens covers for added protection during storage. Another bonus of this red dot optic is that it comes with a skeletonized lightweight riser mount set for an absolute co-witness with iron sights.