In Counter-Strike 2, a Counter-Terrorist takes five seconds to defuse the bomb with a defuse kit.
The kit cuts the normal defuse duration in half. That difference is strategically crucial because a player may be able to complete a kit defuse after winning a retake, even when there is not enough time for an unequipped teammate to finish.
Defusing requires the player to remain within range of the planted C4 and hold the defuse action. Taking damage, moving away, or being eliminated interrupts the attempt.
The kit does not make the player immune to enemies or to the bomb explosion. It only changes the time required for the interaction. Counter-Terrorists can buy kits before the round or pick them up from the map after another player drops one.