1. 【3 in 1 design】 - This is a multifunctional device. In summer, it helps lower the temperature. While in winter, it works as a humidifier and air purifier to avoid dry air, reduce dust and smoke 2. 【Less noise】 - Our USB air conditioner offers three wind speeds. The higher the speed, the better the cooling effect. According to our test, speed of level 1 is absolutely bearable at night. We therefore recommend that you choose level 1 when you sleep 3. 【Wireless running, longer working hours - Our mini air conditioner has a built-in battery, so you can continue to use it if there is no power outlet. The charging time is approximately 3 hours. After fully charged, speed of level 1: working hour is about 8 hours; Level 2: working hours is approximately 4.5 hours; level 3: working hours is approximately 2.5 hours 4. 【Portable, Can be taken anywhere】 - The size of, Our cooler fan is portable, It is good to take it to the office and camping. It is also great as a desktop fan since it doesn't take up too much space. 5. 【Better cooling effect】 - Either you use it with water and the slats or you use ice cubes without the slats. Both work well. It cools the air through the evaporation energy of the water.