This type of Guardian is found exclusively inside of Hyrule Castle. They are similar to Decayed Guardians, since they cannot move and only activate once Link draws near, however the Turret has the same health pool as a Guardian Stalker, whilst also having a larger range.
The Guardian stays dormant whilst not in combat, and when it senses Link nearby, its body will extend, much like a Guardian Scout.
Like Beamos that have appeared in modern Zelda games including Skyward Sword, Link is able to defeat this creature by shooting its eye with the use of a Bow and Arrow. Ancient Arrows in particular are very powerful against these enemies, since one successful shot to the eye will take it down instantly.
Other strategies that can be used to defeat Guardians include utilizing the Perfect Guard ability, where Link can deflect the Guardian's laser with his shield at the right moment to take down the enemy upon three successful deflects. Link should be wary though, since if he fails to Perfect Guard, the laser may still hit him and cause significant damage. The Master Sword is also a sound weapon to use against the Turret, as its damage elevates to 60 whilst in close proximity of one.