Compact, self-contained boresighting system projects a bright red laser beam aligned with the bore axis for sighting scopes, holographic red dot sights, and “iron” sights to the point-of-aim without firing a shot. A powerful magnet holds the sighter securely on the muzzle of any rifle, pistol, or shotgun; nothing to insert into bore or chamber. Install the three batteries (included) into the battery compartment, use the centering guides on the rear of the boresighter to center it on the muzzle, and switch on. Aim at a target 20-30 yards away, and adjust windage and elevation of the scope or sights so point-of-aim is zeroed on the dot. Go to the range for test shots and final sight adjustments. Fits easily in pocket and includes padded nylon carrying case. SPECS: High-impact polycarbonate, black. Laser wavelength, 632-650 nm. Sighting range, 15-100 yards. Dot size, 2” at 100 yards. Includes (3) AG13 button cell batteries, nylon carrying case, and instructions.