The Pet Corrector can be used for:* Unwanted barking.* Jumping up.* Stealing food.* Place avoidance.* Aggression.* Cats Snakes, insects and birds such as geese use the hiss sound to drive off predators and our domesticated pets have the same sensitivity to this sound.The Pet Corrector mimics this hiss sound to interrupt the undesirable behaviour.Canister of harmless gas.When nozzle depressed, hiss sound is emitted.Full instructions and user guide included. Option: Holster for 50 ml and 30 ml bottlesSize:30 ml, 50 ml, 200 ml