Chaff Grenade
From the Metal Gear Wiki
Chaff Grenades are a miniature chaff dispenser. Chaff consists of small aluminum strips that are specifically designed to confuse radar frequencies, and normally used by aircraft to fool missile radar. The individual strips are cut in such a way that they wreak havoc with radar's transmitted frequencies. The Chaff Grenade is a combination of a wide-dispersal system for such strips and an electronic jamming system similar in effect to a magnetic pulse; it fools most electronic devices in the current room, including security cameras, radios, and some types of UAV.
Solid Snake and Raiden used these in their missions to help slip past surveillance cameras, and CYPHERs. They also assisted in confusing Gekkos and Scarabs. During the Shadow Moses incident, Solid Snake used them to disrupt Metal Gear REX's targeting abilities, opening a window of opportunity in which he could attack it; Raiden used them in a similar manner while fighting the Metal Gear RAYs guarding Arsenal Gear. During Operation: Snake Eater, Big Boss also used them to disrupt Colonel Volgin's electrical field. Chaff grenades can also interfer with radio signals and prevent enemies from calling in reinforcements temporarily. By 2014 it has be come a very limited and a hard to find weapon as Old Snake only found some at the abandoned Shadow Moses Island.
