Off to Ecosystem's Unlimited
It shoots a ball of stuff we call squawk gel. Thousands of tiny transmitters in a super glue goo.
It has enough impact to let a person know they've been hit. The transmitters shut down electric motors by putting their controllers into maintenance mode.
They also flag you as hostile to site security, which goes from non lethal to progressively lethal as long as the painted target keeps moving.
Which explains why your guard towers have both pie throwers and plasma cannons.