PetSafe Citronella Disposable Spray Refill Cartridge is a safe and effective way of stopping dogs from barking excessively. The cartridge, attached to the collar barking releases a spray of harmless Citronella that interrupts your dog’s pattern of barking. Over time, most dogs are gradually conditioned to stop barking as the spray acts as a deterrent to the dog. With this solution, you can take your dog out by the water without the concern of nuisance barking. Directions for use: To refill the collar, make sure the unit is turned off. Hold the spray can upright and firmly press the nozzle down into the refill port. Hold for 15 seconds and remove. If spray leaks out, you may need to press harder to complete the seal. About PetSafePetSafe offers a wide variety of pet care products under its three home brands, Drinkwell, easy walk and Frolicat. The products include containment systems, training systems, waste management products, accessories, pet games and toys and travel, access and mobility products.