Barrett Optical Ranging System is an integrated electronic ballistic computer that couples directly to the Leupold Mark 4 rifle telescope acting as the upper rear scope ring. Measures air temperature, barometric pressure and bore line angle. Calculates a ballistic solution for a specific user-selected cartridge. Fits these non-illuminated scopes: Leupold Mark IV 3.5-10x40mm LR/T M1, Mark IV 4.5-14x50mm LR/T M1, Mark IV 6.5-20x50mm LR/T M1, Mark IV 8.5-25x50mm LR/T M1 and Mark IV 8.5-25x50mm ER/T M1.
