ZENIDOG® Gel Diffuser mimics the natural, calming pheromones released by nursing mother dogs. The calming effect helps dogs of all ages feel comfortable and secure in stressful situations. ZENIDOG® Gel Diffuser allows for 2 months of calming effect. It is portable and can be placed where your dog spends most of its day. Diffusion may vary depending on environmental conditions. Replace every 2 months. ZENIDOG® Gel Diffuser is not recommended for use with hyperactive or aggressive dogs. If you’re unsure, consult a veterinarian