The SPARC II derives its name from (Speed Point Aiming for Rapid Combat), which we feel fits the mode and mission of the unit to a tee. The SPARC II is a very versatile unit and is primarily mounted on anything from an AR-15,shotgun to a bolt action rifle for close engagements. This unit is built tough and rugged, manufactured from a single-piece body, and machined from aircraft grade aluminum. The optic has a o-ring sealed for waterproof and fogproof performance. The SPARC II has digital rear facing controls for powering on/off and adjusting the 2 MOA daylight bright red dot brightness at ten intensity level which automatically returns the unit to the last dot intensity used when it was last powered up. The SPARC II Red Dot has a very versatile multi-height mount system which accommodates most firearms including AR-15s needing absolute or lower 1/3 co-witness heights, and mounts on standard Weaver or Picatinny bases (not included). A modular three-piece base offers four separate mounting heights for user- and weapon-specific customization: 18.0 mm (.709 inches), 21 mm (.823 inches), 37 mm (1.457 inches), 40 mm (1.575 inches).