The M203 Thunder Grenade is the first paintball grenade built to utilize an already existing full product line of Grenade Launchers. The M203 Thunder Grenade fires up to 25 paintballs at once, but can be operated with as few as 1 paintball(s). Get within 25 feet of an opponent and let the paint fly. The M203 Thunder Grenade can operate on both CO2 and Green Gas. CO2 offers 800 PSI, while Green Gas only offers 100 PSI. For the best results, use your M203 Thunder Grenade Charger to fill each M203 Thunder Grenade with CO2.