A laser sight is a device attached or integral to a firearm to aid target acquisition. Unlike optical and iron sights where the user looks through the device to aim at the target, laser sights project a beam onto the target that provides a visual reference point. Although lasers in the visible part of the spectrum are most common, invisible infrared (IR) lasers may be used in conjunction with a night vision device.As they are offset from the barrel, laser sights need to be zeroed in, much like a conventional sight, so that the beam intercepts the point of impact at a chosen distance. Devices may include one or both types of laser, with some models also incorporating a rangefinder, flashlight, or IR illuminator. Laser sights may be attached to the existing sighting mechanism, the trigger guard, via a rail system, or can be integrated into replacement components such as the guide rod or grip plates.Some variants are also incorporated into other attachments such as foregrips.
Laser sights are primarily used by military and law enforcement, although have some civilian use for hunting and self defense. They are also found on some less lethal weapons, such as Taser electroshock weapons.