The Firefield .243/ .308/ 7.62×54 In-Chamber Red Laser Brass Boresight is a compact, ightweight boresight with a durable brass construction. The Firefield in-chamber red laser brass boresights deliver precision accuracy without wasting time and ammo at the range. Once placed in the chamber of a firearm, the red laser dot appears exactly where the barrel is pointed, allowing the weapon sight to be adjusted to the theoretical impact point. It’s easy to pack and carry it wherever you go, from the range to the field.