This is a grenade launcher that fires globes of foul blue ectoplasm. Any SupernaturalCreature hit by it becomes paralyzed for a number of sequences equal to the Outcome of your attack. If the victim of a wave suppresser hit suffers WoundPoints while paralyzed, it can make an Magic check (with your Powers AV as the Difficulty) to attempt to end the effect prematurely, adding the number of Wound Points suffered to the Action Result. It makes one check per Wound Point-dealing attack.
Concealment: Trenchcoat