Barrett has gone all out with their BORS system to create a ballistics computer system that easily operates out in the field. The Barrett Optical Ranging System attaches to a variety of rifle scopes, and they fit over the elevation knob to work in tandem with the rifle scope once the computer is activated. The Barrett BORS is designed to compensate for temperature and barometric pressure, and the computer will accurately gauge angle cosines and help prevent rifle canting. Best of all, these remarkable devices are easy to operate and only require elevation knob adjustment to bring the right trajectory to your rifle. Upgrade your rifle scope with a superb BORS system today for less when you shop with Webyshops. As a bonus, we'll ship your order with free ground shipping as long as your order applies. Receive FREE Ground Shipping on all orders over $39.99.