Vector Optics Bore Sighter Features For 7.62x39mm Caliber, Cartridge Style, Convenient and Accurate, Brass Material Brief Introduction: By project a laser beam from the center of the barrel axis of firearm, this laser bore sight collimator allows you to instantly & accurately set your sight or scope etc. The laser light emitted from the laser bore tool travels in a straight line while the bullet follows a trajectory. Even though the use of this device will get you very close, final adjustment should be made at the range. Model: SCBCR-05 Power: <5mW Wavelength: 650nM Weight (net): 14g (0.5 ounces) Length: 38.5mm (1.5 inch) High quality brass in durable finish Already set center aligning in factory Package Including: Instruction, laser bore sight, 4 pcs AG3 Battery