The features you don't see immediately make the difference in the SIG SAUER SIERRA3 BDX Rifle Scope. Behind the HDX advanced optics using HD glass with SpectraCoat ultra-wide broadband lens coatings and inside the 30mm aluminum tube is the power-saving MOTAC sensor for enhanced battery life, LevelPlex digital anti-cant and KinETHIC kinetic energy transfer indicator. The integrated BDX Ballistic Data Exchange in the SIERRA3 is compatible with the BDX-enhanced series of rangefinders. It simplifies targeting by combining the ballistics, environmental conditions and Bluetooth functionality to calculate the holdover dot on a Digital Focal Plane. The second focal plane stadias with OLED illumination will automatically scale with zoom at any magnification level. From ranging, to targeting, to impact, SIG SAUER optics connect the dots. SIG SAUER Electro-Optics Infinite Guarantee SIG SAUER Infinite Guarantee is an Unlimited Lifetime Guarantee that is fully transferable. There is no time limit, no charge and no receipt required. SIG SAUER will repair or replace your optic in the event it becomes damaged or defective, at no charge to you. If SIG SAUER cannot repair your product, they will replace it with a product in perfect working order of equal or better physical condition. It doesn't matter how it happened, whose fault it was, or where you purchased it. HDX advanced optical systems with High Definition (ED) and High Transmittance (HT) glass provide ultra-high resolution and light transmission MOTAC motion sensing technology powers up the illumination when needed to extend battery life SpectraCoat ultra-wide broadband anti-reflection lens coatings reduce surface reflections to extremely low levels across the entire visible spectrum Innovative KinETHIC kinetic energy transfer indicator shows you when the energy to target drops below inchclean-kill inch levels for more ethical shots LevelPlex digital anti-cant system utilizes a