Chamber the Sightmark 17HMR Boresight in your 17HMR rifle like a regular cartridge, and a red laser dot shows exactly where you're aiming. Ideal for hunters, competitive shooters and law enforcement, 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, two (2) AAA batteries, and instructions. Features: Precision accuracy Reliable and durable Fastest gun zeroing and sighting system Reduce wasted cartridges and shells Compact and lightweight Easy to pack and travel External battery pack with slide switch operation