The Barrett Optical Ranging System (BORS) is an integrated ballistics computer that mounts directly on the riflescope and couples to the elevation knob. BORS instantly takes care of the data work by drawing from several tables and taking into account a number of real-time external factors so you can focus on the task of achieving first round hits. The kit includes the proprietary Barrett Ballistic PC Software that's pre-programmed with a library selected by Barrett. BORS USB data cable allows the transfer of user programmable custom loads to BORS from his or her computer. This BORS unit comes complete with a Leupold Mark 4.5-14x50mm scope, along with Barrett Ultra High Rings.