UP100 Brass CAL: .243/.308WIN/7MM-08REM Caliber Cartridge Laser Bore Sighter Red Laser Boresighter Easy-to-use, self-contained boresighting system fits in the chamber of your rifle or pistol and projects a powerful red laser beam aligned with the bore axis for sighting to the point-of-aim without firing a shot. Works with scopes, holographic red dot sights, and variety sights. Precision accuracy,Material: Brass Maximum output power: &lt;5mw, FDA & Amazon Standards Type: Class IIIa Laser wavelength: 626-660 nm. ; Operation: On/Off End Cap