The original explosives set by Bond and Wai Lin have been discovered and de-activated by Carver, so Bond uses a grenade, identical to those included in this lot, to cause the exploision needed to reveal the stealth boat's location on the radar of both the British and Chinese navies. He takes a detonator from his wristwatch and tapes it to the side of the jar containing the grenade. After Carver has killed Gupta he tells Bond "You see, I have a back up plan", to which Bond replies, "So do I", twisting the bezel on his watch which detonates the grenade.