Sig Sauer Romeo-MSR is a sealed compact green dot sight intended for MSR, carbine, shotgun and air rifles. Features- brightness is adjusted with a top-mounted rotary dial; 10 daytime and 2 night vision settings; high-performance lens coatings for excellent light transmission and dot contrast; unlimited eye-relief and parallax-free operation; see-through flip-backs; 1.41" T10 Torx M1913 skeletonized lightweight riser mount for absolute co-witness and top loading battery compartment.