They are the basic type of Belltower Spec Ops, first encountered in the prologue, during the attack on Sarif Industries, supporting the Tyrants. This is also their main role in the game - they are deployed in Highland Park, Picus TV headquarters and Omega Ranch. In all three locations, Adam Jensen eventually fights a member of the Tyrants. In areas of lesser importance, they are substituted by regular Belltower mercenaries.
Later in the game, Spec Ops are deployed with Ogres and Sneakers. Some come equipped with cybernetic arms, but the majority remains non-augmented. Their toughness is on par with regular medium Belltower mercenaries, but they are usually better equipped, utilizing submachine guns, combat rifles and sniper rifles.
They have no major strengths and as with regular Belltower operatives, can be killed with practically any weapon. They utilize more advanced tactics than other enemies and will attempt to flank Jensen, use grenades to flush him out and move as a squad. They lack helmets, so headshots can kill them easily. Staying in cover is advisable though, as their automatic weapons can be dangerous, especially if they're in a group.