Kozak is equipped with a MR8 assault rifle, and a cloaking device in the Operation Overlord trailer.
In Future Soldier He can be equiped with a Sniper Rifle, Assault Rifle, Shotgun, Pistols, Personal Defence Rifle, Light Machine Guns and Sub Machine Guns before a mission.
Notes
He participated in Operation: Take Down Overlord.
A replica of his gear in the most recent version of Ghost Recon: Future Soldier was available during E3 2011 for Xbox 360 avatars. It sold for 400 Microsoft points.
He may be named for Kozak the Magician
His full name is John Dimitri Kozak
His mother and father are from Russia
In the final game Kozak appears to replace Bones using the drones instead of him
In reality Cossacks are a group of predominantly East Slavic people who originally were members of democratic, semi-military communities in Ukraine and Southern Russia. Cossack, it sounds the same but it's spelled differently.