Comfort Zone Calming Multi-Cat Diffuser Refill. Feline stress can lead to all sorts of problem behaviors like scratching, urine marking and fighting. This diffuser refill works with the complete kit, and uses a clinically-proven formula that ?smells? like the natural soothing pheromones cats use in the wild to signal safety. It?s a drug-free, unscented and odorless vapor that can be diffused into the air. Your kitties will react to it as if it were the actual pheromones, to help them feel more calm and relaxed, and help reduce multi-cat tension. It?s also perfect to use during stressful times for your pal, like when traveling, going to the vet, while moving, or when bringing new pets home. Plus, it?s totally safe to use and won?t affect any other pets, including Fido?although he may also enjoy a more calm and relaxed kitty himself. Diffuser refill works with the Comfort Zone Calming Multicat Diffuser Kit to help cats feel more calm and relaxed. Odorless, drug-free formula mimics natural cat pheromones that signal a safe environment they can relax in. Clinically proven to help reduce stress-related and territorial urine marking, scratching and fighting, and is also great for vet visits, moving, getting new pets or when traveling. Easily vaporizes into the air when used with the diffuser for your cats to ?smell? and react to. Won?t affect any other pets so you can use it around dogs and anywhere in your home, and doesn?t leave any scent behind. Refill bottle is compatible with Comfort Zone with Feliway Diffuser.