Passage: By the time of the SLA shootout, SWAT teams had reorganized into six 10-man teams, each team being divided further into two five-man units, called elements. An element consisted of an element leader, two assaulters, a scout, and a rear-guard. The normal complement of weapons was a sniper rifle (a .243-caliber bolt-action, based on the ordnance expended by officers at the shootout), two .223-caliber semi-automatic rifles, and two shotguns. SWAT officers also carried their service revolvers in shoulder holsters. Standard gear included a first aid kit, gloves, and a gas mask. At a time when officers were usually issued six-shot revolvers and shotguns, it was a significant change to have police armed with semi-automatic rifles. The encounter with the heavily armed Symbionese Liberation Army, however, sparked a trend towards SWAT teams being issued body armor and automatic weapons of various types.

Question: What is the standard gear for the face that is being used?
gas mask