Soldiers of the Combine Overwatch in Half-Life 2. Equipped with thicker body armor than Metrocops, tinted eyewear gas masks, and stripped of much of their humanity under their clothes- referred to as transhuman forces.
The normal variety possess grey armor and blue-tinted eyewear, prison guards possess blue armor and yellow-tinted eyewear, and shotgun users possess grey-red armor and red-tinted eyewear.