thunder b starter pakke multiThunder B has created a really smart system for their grenades that goes bang. You simply put a CO2 cartridge in the Core that comes with it and screw on one of the shells. Once that's done, you just wait for the right moment to throw your grenade. When you pull the split and throw, it goes bang when it lands. It makes a bang thud of over 130 db. The shell you are using cannot be reused, but the core part of it can, without any problems. Includes 3