Human Slingshot

The Human Slingshot was a weapon developed and used by the Militaires Sans Frontieres. It was a weapon with enough power to launch even a brawny, 200-pound soldier a considerable distance, and at a high enough velocity to heavily damage various vehicles upon impact. Its main components were sling posts and a sling band, and was primarily developed for use in CO-OPs, although the sling post can also be used as a good substitute for a baseball bat or a club if used in a solo op.

The Militaires Sans Frontieres developed this weapon upon procuring a Tigrex fang as well as various levels of Gear REX's acidic mucous, of which the latter ingredient required a lot of distilling before it could enhance the sling band to its maximum potential.

Gameplay
If the player uses the Sling Post as a club against enemies, Miller will call stating with shock that that wasn't what the sling post was supposed to be used for.

In-game descriptions
"One of the structural elements of the human slingshot, the ultimate CO-OP weapon. With enough mechanical strength to withstand the rigors of the giant rubber band that comes with it, it can also makes a fine club for beating down the enemy."

- Human Slingshot Post weapons description from Metal Gear Solid: Peace Walker

"One of the structural elements of the human slingshot, the ultimate CO-OP weapon. The rubber ban is incredibly powerful and can launch a brawny, 200-pound soldier a considerable distance. The power of the launch depends on how rapidly the button is tapped. Players with weak thumbs may want to practice their button mashing skills before attempting to use this weapon."

- Human Slingshot Band weapons description from Metal Gear Solid: Peace Walker