Chamber the Sightmark Laser Boresight in your 8mmx57 JRS rifle like a regular cartridge, and a red laser dot shows exactly where you're aiming. Ideal for hunters, competitive shooters and LE, this device significantly reduces wasted cartridges and shells. Simply adjust your sights or scope, and save your extra ammo for the hunt. Includes a carrying case, three (3) AG3 batteries, and instructions.