Thunder B Airsoft CO2 Simulation Grenade (Package: 3 Shell Set / Flashbang)Features Low impact CO2 air burst is safe and effective One time use shells are easy to replace Non pyrotechnic design ideal for use in all weather and environments Core design uses replaceable 12gram CO2 cartridges Fits in many different style "flash" grenade pouches 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