Gas Mask

A gas mask is a mask put on over the face to protect the wearer from inhaling "airborne pollutants" and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Some gas masks are also respirators, though the word gas mask is often used to refer to military equipment. Early known gas masks dates back to 1799 with respirator like masks used by miners in Prussia (modern day Germany).

Battlefield 2: Special Forces
Gas Mask is a tool featured in Battlefield 2: Special Forces available to all classes. The gas mask shields players from Tear Gas. The mask can be worn by pressing on the keyboard. While there is no time limit for use of the gas mask, it limits the user's field of view, mostly near the bottom of the screen and also increases the rate of stamina depletion, decreasing the amount of physically demanding activities the user can perform in a time period. The gas mask counters the Support kit's tear gas launcher. The gas mask must be worn when entering any gas cloud regardless of what side the person that fired the canister was on.

Singleplayer
The Gas Mask is used in the Singleplayer campaign of Battlefield 3 during the mission Comrades. Dima and his GRU teammates, Kiril and Vladimir place their gas masks over their faces when the PLR released nerve gas in the stock exchange building. Gas masks are also worn by the PLR in the said mission.

Co-op
Gas masks are worn by Snake 6-6 and the PLR in the mission The Eleventh Hour for the majority of the mission.

Multiplayer
In Multiplayer, the gas mask does not play a major role. It is worn by the Spetsnaz engineer. the mask is a MCU-2/P Protective Mask.

Trivia

 * Strangely enough, in Battlefield 3, the Gas Mask's appearance and detail has the highest graphical difference; In the lowest setting under Effects Quality, only the outlines are shown without any glass or reflection. What you see on the image above is the Gas Mask on the highest or Ultra graphics settings