A saw-off version of the famous break-action grenade launcher, M79. The M79 were widely used by the American forces in the Vietnam War. This operator can easily hit the targets in 200m. It was still in used by the Navy Seals although it has been replaced by the M203.
This is a modified version of a grenade launcher that fires flame flare. It holds 5 rounds for each round with 40mm flare and its mobility has been increased by cutting the gun barrel and butt plate. The secondary fire mode can make the grenade bounce before exploding.
JANUS-1 is a grenade launcher categorized under the pistol slot and developed by Aegis Institute. It is fed with 5 rounds of 40mm grenade and is equipped with the Janus Transformation System which enables the weapon to continuously fire unlimited rounds for 5 seconds. However, the system only activates after all initial grenade rounds are used up (and hit) on a target. The weapon's Janus form has greater firepower and rate of fire.
M32 MGL is a lightweight grenade launcher, fed with 40mm grenades, a revolver-style semi-automatic grenade launcher with 6 slots. The second firing increases the range and the rate of fire.
FG-Launcher (Firecracker Grenade Launcher) is a grenade launcher modified from a firecracker fed with 10 rounds of 40×46mm grenade. If an enemy is near the blast radius of the launched grenade, they will experience a disorienting screen shake.
Others
M203: An underbarrel grenade launcher which is the successor of the M79. It was widely used from the 1970s to present. The M203 is usually attached to the M16 and M4rifles, although it's also available to be attached onto other rifles. In Counter-Strike Online, the M203 appears as a part of the SVD Custom and the OICW. The M203 does very high damage and even be able to blow-off enemies at close range.
THANATOS-5's grenade launcher: Unknown by name, this is an underbarrel grenade launcher that can only be used when Thanatos Blade System is activated. It fed with a special grenade type known as THANATOS Grenade.