Holographic weapon sights work by using laser technology to project an image of a reticle onto a sighting pane, assisting the shooter in target acquisition. They are often battery operated in order to keep the overall unit small enough to boost customizability and give rifle owners more space on their rail for other addons. 

Holographic Battery Operated Rifle Sight

 These special sights are tools used by soldiers and special forces units around the world for their reliability and the increased lethality they impart to assault rifles. 

This particular laser powered rifle sight is specially with parallax free lighting - which means that you will be able to see a clear reticle no matter the position of your head in relation to your sight. 

Shooters employ these kinds of sights to improve the speed at which they can acquire targets within medium range encounters and shooting situations.

Sights like the one pictured are best used for quickly acquiring targets up to 100 yards away. The combination of the sharp red laser image being projected onto clear glass makes it easy to not only focus on your sighted target, but also simultaneously maintain situational awareness. 

One downside to keep in mind about these compact holographic sights is that they gain their small size by being battery operated. You can still expect about 600 hours of continuous use from one of the top of the line models such as this EOTech XPS2-0 Holographic Sight pictured above.

EOTech XPS Holographic Sight Mounted

You can see from this image below that even when mounted the sight does not take up a lot of room.  It is a small add-on that conveys a lot of utility in terms of quickly sighting over medium distances. 

High quality compact laser rifle sights like this will run anywhere from $500 on the low end to upwards of $800. 

They are also commonly referred to as red dot sights or red dot laser sights. In popular culture they are associated with special commando teams and elite strike forces. 

They are favorites of police SWAT teams who operate in small enclosed urban environments where encounters are fast paced and likely to be in close quarters. 

Laser dot sights for rifles and submachine guns can help improve accuracy and reduce the likelihood of harming an innocent civilian or missing the mark during a heated encounter. For sport shooting, the ability to quickly and accurately acquire targets down range makes these compact holo sights a favorite amongst enthusiasts.