diptyque Roses Refill for Electric Diffuser refills the electric room diffuser and pays homage to the queen of flowers, evoking the fragrance of a freshly picked bouquet. It will keep for up to 3 months after opening if the package is resealed after each use. The duration is approximately 40 hours (up to 80 cycles since the electric fragrance diffuser activates 3 times in each one-hour cycle alternating 10 minutes of activity with 10 minutes of rest).