The Pura 4™ smart fragrance diffuser uses innovative smart features paired with premium, clean scents to give you the most modern, customized, and high-end scenting experience possible. Simply insert your smart fragrance vial and Pura 4 automatically detects the fragrance, creating a seamless swapping experience. Enjoy 2 fragrance vials for up to 6 weeks when diffusing 6 to 8 hours per day. Note Pura 4 is only compatible with Pura fragrance refills, fragrance vials are not included.