G-Sight BSG-270 .270 Wsm Laser Bore SIGHT - Gold Plated - Button Activated, Gold Finish Less than 5 mw, constant "on" laser for sighting in optics 635 Nm wavelength/ Class 3A laser &lt; 5mw Laser is activated when bolt carrier Group applies pressure to the back button/ not intended for dry Fire training Gold finished high quality brass Batteries included