Defuse kits were first added in BETA 4.0, but later got reworked and added as a purchasable item in BETA 5.0. Originally, half of the Counter-Terrorist team would get defuse kits for free, without which the bomb could not be defused. In BETA 5.0, the defuse kits were changed to be purchasable by any Counter-Terrorist player, and they were no longer necessary to defuse the C4. They can only be purchased by Counter-Terrorists on bomb defusal maps. It halves the time required to defuse the bomb (five seconds instead of the usual ten). It is automatically used when defusing the bomb and can be used an unlimited amount of times.
Possessing the defuse kit adds a symbol of a pair of pliers to the player's HUD under the player's inventory. In Source and Global Offensive, when playing as a Counter-Terrorist or as a spectator, the scoreboard shows a defuser icon next to the name of the player for players possessing a defuse kit.
If a Counter-Terrorist dies, their Defuse Kit will be dropped, and other Counter-Terrorist without a Defuse Kit can pick it up. Interestingly, if a CT begins defusing the bomb and had somehow picked up a defusal kit at the same time, the C4 will still require 10 seconds to defuse and not 5. This can be done by jumping on the C4, begin the defusal process, and then obtaining the defusal kit. However, if the defusal process is restarted when following the aforementioned fact, the bomb can be defused in 5 seconds.
It is often highly recommended to purchase a kit as a Counter-Terrorist to reduce the time it takes to defuse (this is especially helpful when "ninja" defusing). If a team is tighter on economy, then it is also viable to only have two players purchase defuse kits, one stationed at each bombsite to defuse the bomb when the site is clear, or let others pick up their kits to defuse if they die.
The Defusal kit is the standard equipment in Deleted Scenes. The player will automatically use it when defusing a bomb, and the defuse time is same as in multiplayer (5 seconds). However, the suitcase Nuke and sometimes bombs can also be defused like the C4 but slower and the time needed to defuse is same as defusing C4 without a kit (10 seconds).
In the Counter-Strike: Condition Zero Tour of Duty campaign, the CT bots will never buy a defuse kit. However, they will pick it up if a defusal kit is dropped in their pathways.
- Rarely in Counter-Strike and Condition Zero, the buy menu can become buggy, showing the item available to terrorists. However, trying to purchase the defuse kit as a terrorist will display the message, "The 'Bomb defuse kit' is not available in your team to buy." This may be more common if the player has custom options of loadout.
- In the CS:GO official trailer, a GSG-9 operative is seen using a defuse kit.
- Similar to the C4 bomb, the defusal kit can be seen on the player in third-person but less noticeable (it is strapped on the waistline of the player).
- In Counter-Strike: Global Offensive, the code of the C4 (7355608) is written on the bag of the kit.
- In Global Offensive beta, the defusal kit was randomly given to two Counter-Terrorists, similar to how the original defuse kits were given to half of the Counter-Terrorist team in Beta 4.0 .
- CS:GO Defusal Kit at CSGO Replays