Aroma pads for custom fragrances: Add your favorite essential oil to enjoy fresh scents while humidifying the air. Long-lasting fragrances: Dreo aroma pads effectively diffuse scents for a longer time, providing a fresher environment. Designed for humidifiers: The aroma pad tray keeps oils separate from the water tank, preventing malfunctions. Natural and safe materials: Made of pure natural fiber cotton, the pads are harmless to humans and the environment. Replacement cycle: Replace pads every 1-2 weeks to prevent mold and maintain fragrance quality. Compatible with Multi-models: Dreo Humidifiers HM311/HM311S/HM512S/HM713/HM713S