The Combine Overwatch is the primary military force of the Combine on Earth. It consists of biomechanically enhanced humans, who wear heavily padded long-sleeve body armor and gas masks. The markings on the suit change depending on each individual unit's assignment and rank. Elite Combine soldiers wear bright white armor with one red eye, while the majority of soldiers wear blue armor. Shotgun units wear similar armour to the standard Combine Soldier, but coloured brown with orange eyes. They are armed with a variety of firearms, including shotguns, submachine guns, sniper rifles and pulse rifles. Overwatch soldiers usually operate in small groups, using squad tactics and grenades to flush out and flank the player. They occasionally provide support to Combine synths, and often travel to areas by use of dropships. They use radios to communicate with each other and with Overwatch headquarters. Combine Overwatch soldiers are usually encountered outside City 17, and only appear in the city after "The Uprising" near the end of "Half-Life 2".