The Semtex is a piece of equipment from Call of Duty: Modern Warfare 2, as well of a Lethal Grenade from Call of Duty: Black Ops. It is like a frag grenade except it is sticky and attaches itself to the first thing it hits, whether that is a surface or an enemy. It has a much shorter fuse than the frag, about 2.5 seconds, but it cannot be cooked. Also, unlike a frag, it can be retracted if Y (change weapon) is pressed whilst RB is held down. It has slightly more damage than a frag grenade, and this is often the deciding factor when a player is choosing between the two. Finally, the other point differentiating the two is sound; the frag makes a distinctive click when the pin is pulled, as well as a metallic sound when it impacts a surface. The Semtex does not makes any sound being armed or on impact - but it does emit a regular beeping sound which can notify enemies of its presence.
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