Electromagnetic Net

The Electromagnetic Net, referred to as the EM Net for short, is a device used by the Militaires Sans Frontieres to capture enemy vehicles. Upon activation, it generates a powerful magnetic field that is several teslas in magnitude, enough to freeze regular enemy ground vehicles in their tracks temporarily. Upon doing this, it also releases four devices that, when activated before the magnetic field shuts off, can activate fulton recovery balloons on each corner of the net and presumably transport it away by one of the MSF's choppers.

It was originally intended during the 1974 Peace Walker Incident to be developed by the American Forces. However, the Militaires Sans Frontieres managed to procure the design specs after neutralizing a Peace Sentinel Custom MBTK-70 unit in Bananal Fruta de Oro and developed their own copy. They also had trouble mass producing them in large quantities, thus making only one EM Net available for field use per mission.

Gameplay
If the player manages to complete a vehicle mission using the EM Net, it won't grant the player an "S" rank due to using the EM Net.

In-game weapons description
"A high-power electromagnetic net used to capture large enemy war machines. When activated, it generates a powerful magnetic field several teslas in magnitude, freezing enemy war machines in their tracks. While being able to capture enemy weapons without damaging them is great, each net can only be used once and they are too difficult to produce in large quantities, so be sure not to waste them. Make each one count."

- Electromagnetic Net weapons description from Metal Gear Solid: Peace Walker