The SL-500 is an ideal tool for professional hunters, shooters and gunsmiths, offering superior Boresighting accuracy with its ultra-bright green laser. This laser is 50 to 100 times brighter than traditional red lasers, making it far easier to see in daylight conditions. Powered by a DL 123 lithium battery (included), the SL-500 provides up to 10 hr of continuous use. Using the latest laser technology, it ensures precise alignment, while super-strong magnets in the arbor securely center the laser in the muzzle for consistent accuracy. Its versatile design includes a system of adapters and O-rings, fitting firearms from .22 to .50 caliber handguns and rifles, as well as 20 and 12 Gauge shotguns and muzzleloaders, making it a valuable tool for a wide range of applications.