The CTS-1300 open red dot sight for rifles and shotguns has been designed for easy acquisition and rapid engagement of close to medium range targets. The sight boasts a crisp 3.5 MOA round aiming dot with a high efficiency LED for years of use. The easily accessible external battery compartment allows for the replacement of batteries without removing the sight. The CTS-1300 is ready to mount right out of the box, with an industry standard mounting interface. The thoughtful and innovative designed sight is shock, impact, fog, and vibration resistant. The entire Crimson Trace Electronic Sight line is part of the FREE Batteries For Life program and are covered under the 3-year Protection Guaranteed Warranty.