Fuel Your Dual150 with Levoit Humidifier Replacement Filters Levoit Humidifier Replacement Filters/ Levoit Water Filter Sponge Why to use: Capture and filter fine impurities and particles to improve humidifying efficiency in a healthier way. When to change: Generally lasts 1 month depending on hardness of water. Where to buy: Please search B09ZY9N6PD or "LEVOIT 10-Pack Humidifier Replacement Filters" on Amazon. Troubleshooting: 1.Do I need to use distilled water? Yes, we recommend using purified or distilled water to avoid white dust or possible hums. 2.How should I clean and refill the tank? Please clean your humidifier before first use and replace the water filter on a regular basis to avoid possible mold or mineral build-up. 3.Why is the refill indicator light red when the tank is full? Make sure your water tank and float are in the right place, and the water outlet valve is clean. Feel free to reach us if further assistance is needed. 4.How to use the aromatherapy function? Simply add 10-15 drops of essential oils to the base. Please do not add excessive amount of oil. Specifications: Product Dimensions: 7.2 × 8.1 × 11.6 in / 18.3 × 20.6 × 29.4 cm Product Weight: 3 lb / 1.38 kg Whisper-Quiet Operation: ? 28dB Effective Range: 107-290 ft² / 10-27 m² Material: BPA free, suitable for babies and adults Wattage: 25W Features: ? Large Water Tank of 3L ? Operation that Lasts Up to 25 Hours, 3 Nights of Sleep ? Ultra-Quiet Operation ? 360 Rotating Nozzle ? ETL Certified For Safety and Reliability ? Comes with Cleaning Brush Your satisfaction with our products is the priority of the team. If you find the product damaged or used when you receive it, please don't hesitate to contact us.