The Sig Sauer SIERRA3BDX 4.5-14x44mm Riflescope is comes complete with the BDX Ballistic Data Xchange. The SIERRA3BDX riflescope provides the hunter an illuminated auto-holdover dot on targets when coupled with a Sig Sauer BDX capable KILO rangefinder. Featuring exceptional SpectraCoat lenses, LevelPlex digital anti-cant, and KinETHIC kinetic energy transfer indicator, the SIERRA3BDX 4.5-14x44mm Riflescope is incredibly simple to use. Range a target, put the holdover dot on target, pull the trigger, and then impact.