Sig Sauer Sierra 6 BDX 3-18x 44mm Rifle Scope - BDX-R2 - Built upon SIERRA3 award-winning technology, and the SIG SAUER BDX Ballistic Data Xchange technology, the SIERRA6 family of riflescopes provides the hunter or marksmen with an intelligent auto-holdover specific to their ballistics, target, and environment. Pairing a SIERRA6 to a BDX equipped rangefinder allows users to bring the capability of Applied Ballistics into the field without the need for a mobile device. Features Integrated BDX Ballistic Data Xchange 2.0 with Up to 95% Light Transmission; Advanced HDX 6x Optical System; Automatic Hold-over Dot on a Digital Focal Plane; Ballistic Profiles Compatible with Centerfire, Muzzleloader, and Crossbow Platforms; Innovative KinETHICTM Kinetic Energy Transfer Indicator for Ethical Shots; Dependable Waterproof and Fog-Proof Performance (IPX-7 for Complete; Immersion up to 1 Meter); Argon Purged for an Enhanced Lifetime of Performance; LevelplexTM with Auto Levelplex Mode;