Description - Air Switch KitDesigned for the Scent Machine – ProfessionalThis Air Switch Kit is for spaces that DO NOT have frequent air circulation (fan on once every six hours or less). This will ensure that the scent machine only diffuses fragrance when the fan is on. Compatible with the Scent Machine Pro, sold separately.The Air Switch Kit is an unbeatable way to save money! With its ability to sense when air is flowing, the kit uses less fragrance oil overtime. This air scent diffuser machine add-on will Scent Your Space efficiently by giving a burst of a fresh fragrance of your choice only when it's most important, when the air is on. This results in the Scent Machine Pro using less oil overtime. Less fragrance oil overtime translates to less money being spent to scent both large spaces and businesses!For the installation details, check out the User Guide here.