during the 1990s. The number officially rose to about 20,000 nationwide by 2007; the biggest OMON unit in Russia, Moscow OMON, numbers over 2,000 members. Most OMON officers retire at the age of approximately forty-five. They were also sometimes not paid for their service. In 2001, for example, some fifty OMON members from Moscow filed a lawsuit claiming they had not been paid for one month of combat operations in Chechnya. The use of OMON members in high-risk situations, especially in Chechnya and elsewhere in the North Caucasus, often causes the group to lose members in combat. Equipment OMON groups use a wide range of firearms, including AK-74 assault rifle, AKS-74U carbine assault rifle, 9A-91 compact assault rifle, and PP-19 Bizon submachine gun, and the Makarov pistol, Stechkin automatic pistol and the MP-443 Grach or GSh-18 are assigned as sidearms. OMON units may use other weaponry, typically used by Russian light infantry during special operations and in war zones, such as: the PK machine gun, the GP-25 underbarrel grenade launcher for assault rifle or the GM-94 pump-action grenade launcher, RPG series rocket-proppelled grenade launchers, and the Dragunov and Vintorez designated marksman rifles. The kind of issued protective gear is shared with regular National Guard units. The Bagariy body armor is a common sight replacing the older Kora-Kulon while the ZSH 1–2 is the main issued helmet with the older Kolpak only being used on riot duty. They are sometimes called "OMON soldiers". As riot police, OMON often uses special equipment termed riot gear to help protect themselves and attack others. Riot gear typically includes personal armor, batons, riot and tactical shields, and riot helmets. OMON also deploys specialized less-than-lethal weapons, such as water cannon, pepper spray, tear gas, sponge grenades, pistols, rifles, and shotguns which fire rubber bullets, bean bag rounds, stun grenades, and Long Range Acoustic Devices. Transport OMON vehicles include specially-equipped vans, buses and trucks of various types (often armored and sometimes equipped with mounted machine guns), as well as a limited number of armored personnel carriers such as GAZ Tigr, BTR-60, BTR-70 and BTR-80. Uniforms OMON's headgear remains their signature black beret (they are thus sometimes called Black Berets), which they share with the Naval Infantry. OMON, as part of the RosGvard, is transitioning to the Russian version of the ATACS LE (blue/grey) but units are still seen wearing the traditional Noch-91 uniform in all-black, and blue