In this video, Matt shows how to use the APS/Hakkotsu Thunder B CO2 Sound Grenade. These have disposable shells and available at Evike.com... "Hakkotsu Thunder B grenades have been the industry leading standard in non-pyrotechnic simulation grenade / distraction devices for years. Thunder B grenades use a safety pin / spoon design very similar to a real grenade, with no shrapnel and no pyrotechnics, providing an effective low-impact burst. This sound-type grande is safe for many uses, in all environments and weather. Each shell is one-time-use; simply replace the CO2 cartridge in the grenade "core", thread on another shell and you're ready to rock!"