As an action, a character can throw a grenade at a point up to 60 ft. away. With a grenade launcher, the character can propel the grenade up to 120 ft. away.
Each creature within 20 ft. of an exploding stun grenade must make a DC 15 con save, becoming stunned until the end of its next turn on a failure or deafened until the end of its next turn on a success.