Sig Sauer SIERRA6, Rifle Scope, 2-12X40mm, 30mm Main Tube, BDX-R2 Digital Ballistic Reticle, 0.25 MOA Adjustments, Bluetooth, Black Color SOSBDX62111 Built upon SIERRA3 award-winning technology, and the SIG SAUER(R) 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(R) into the field without the need for a mobile device.