Size: 48ml Does your dog bark excessively Are they pacing, panting, whining or hiding on a regular basis These behaviors may be caused by fear and anxiety. ADAPTIL is a vet recommended, clinically proven, drug free solution that helps your dog feel calmer. The ADAPTIL Calm Home Diffuser Kit provides comforting messages (dog appeasing pheromones that mimic a mother's nursing pheromones) that helps dogs feel calm and relaxed in situations like loud noises (thunderstorms and fireworks), being home alone, traveling or other fearful situations. These odorless messages are only perceived by dogs and provide a strong signal of security and comfort. By making your dog feel relaxed and less stressed, it helps to reduce problem behaviors. Cats and people are not affected by these pheromones. The ADAPTIL Calm Home Refill includes one refill vial (diffuser head sold separately). You should plug your diffuser in the room(s) where your dog spends the most time - each diffuser covers up to 700 sq. feet. Make sure your diffuser isn't covered by curtains, or behind furniture. Each refill can last up to 30 days. For maximum effectiveness, you should replace your diffuser every 6 months. Make sure to follow the instructions when plugging in your diffuser, and plug the diffuser in upright.