Amazon.ca Product Description Tested and recommended by the National Tactical officers Association, the Sightmark .40 S&W Boresight Offers a quick and easy way to sight in your .40 Smith & Wesson pistol. The bore sight can be used as a training aid for "quick draw" drills. Includes a carrying case, three (3) AG3 batteries and instructions. From the Manufacturer The sightmark laser boresight provides the most convenient and accurate method for sighting in pistols of all types. Simply chamber the boresight like a regular bullet and a laser dot will show exactly where the rifle is aiming. It is easy to sight in any scope without firing a single shot. Live fire is only needed to fine tune the weapon being sighted in order to compensate for inconsistencies, such as bullet drop due to distance. Perfect for hunters, competitive shooters and law enforcement, the sightmark laser boresight is sure to take the frustration out of sighting in almost any gun. Iteasy to use and will quickly save both time and money by avoiding prolonged live fire tests at the range; use the extra ammo for honing those shooting skills and for the hunt. A lightweight carrying pouch protects the laser for convenient use in the field. The sightmark laser boresight is available in several calibers and gages for use with most pistols. Sightmark-make your mark.