The Badger Ordnance sniper tool angle cosine indicator kit takes the guesswork out of determining your shot angle. Determine the range to your target, multiply that distance by the cosine value (marked on the ACI with a red dash), and you have the correct distance of angle. Includes both the mil spec Gen-1 angle cosine indicator and the Gen-2 Badger Ordnance ACI mount. Badger Ordnance 306-73A Angle Cosine Indicator Kit w/ Gen II Rail