Claymore x2

Claymore x2 is a Call of Duty 4: Modern Warfare first tier perk that gives a player two trip-activated claymore mines that are manually planted in the ground by the player. When claymores are set up, two thin, short red beams indicate the presence of a claymore, as well as the direction the claymore is facing. A marker with the team's insignia will show above friendly claymores (e.g. winged dagger above a friendly claymore indicates the claymore is of the SAS team). Claymores cannot be activated by friendly players, neither can claymores kill friendly players directly. A claymore is activated when an enemy player moves into close proximity of the red beams on the front of a claymore. There will be a distinct "click" sound, followed by the claymore's detonation 0.83 seconds later. It is possible to activate enemy claymores without being killed (such as by running past the Claymore fast enough to get behind it before it detonates). An enemy claymore can be destroyed by shooting it. Claymores only explode 60 degrees in front of them and upwards. A claymore cannot do damage to someone who is below it or outside of the 60 degree cone.

Tactics
Claymores are best placed so that the red lasers cannot be easily seen, such as in vegetation, a red-colored area (a place illuminated by fire), or around corners. The best example of a well-hidden claymore would be in the red grass near the fire on Bloc, near where Target B is in Search and Destroy.

Claymores are also often used by snipers to cover doorways for them while they snipe. If the intruder is not killed in the explosion, the sniper is alerted by the noise (or the 'x' indicator if the Claymore did any damage) and can often be ready to fight back the now slightly weakened enemy.

One problem with claymores is that even if the enemy doesn't see the claymore and carries on walking, the claymore will click and have a 0.83 second delay before exploding, giving the enemy a chance to jump back and avoid it (unlike a Bouncing Betty in Call of Duty: World at War, which explodes with little notice for the enemy).

A good tactical acceptance is to place Claymores facing a car, standing in a narrow passsage, for example at north spawn-point at mp_crash. Red lasers are located towards car and it's hard to notice them, hard to pass without detonation, and explosion will blow up the car, giving much more damage.

Against Claymores
If you have the Bomb Squad perk equipped it will be easy to avoid the Claymore; but if not there are ways to spot it.

The claymore will beam a red light, being the sensor of the explosive. The red light can be easy to spot, depending on the situation, so you can avoid it. Mentioned above, the claymore will click and have a 0.83 second delay before exploding, giving you a chance to get outside the blast radius. Planting claymores will also produce a clicking sound, telling you that an enemy player is using them.