About This Item NO NOISE: the noise is less than 50dB, much quieter than 90%. When used outdoors or around other people, you will never be embarrassed by loud noise. EASY USE & CLEAN: one-touch operation. Just press a button to turn on / off this steam humidifier. Detachable water cup and mask, easy to assembly and disassemble,Water washable soft mask is super easy to clean. SMALL SIZE: Pocket design, portable and compact. You just need to put it in your pocket, handbag or backpack. Carry! Weighing only 90 grams, it is ideal for travel or children. BATTERY & USB POWER SUPPLY: can be powered by 2 AA batteries (not included), or can be directly connected to an external power supply via a USB cable. (Note: Do not use the battery and USB cable at the same time). SUITABLE for EVERYONE: It comes with a mask for children and adults and a mask that can be used for the whole family. Just remember to disinfect the mask or cigarette holder after use.