The Sleep Gas Satchel was a remote-detonated sleep-gas dispersal device.
Behind the scenes
The sleep gas satchel appeared in Metal Gear Solid 4: Guns of the Patriots as a placeable weapon. Its usage as a remote-detonated weapon made it a non-lethal alternative to C4. Likewise, its design was loosely based on the Italian-made VIS-3.6 blast resistant anti-tank mine.
Be cautious, as the gas will linger for a while after putting soldiers to sleep, unlike the SG Mine. Do not walk into this cloud, as Snake will get knocked out immediately.