USB Rechargeable: With built-in two 4200mAh high-capacity lithium batteries, the fan is USB rechargeable and works for 6-13 hours when fully charged. This mini fan is compatible with all USB ports, so you can charge it from any USB device Five Adjustable Speeds & One-Button Design: The small fan has been innovatively upgraded to five wind speeds to meet your demands in different occasions. Moreover, with the one-button design, it can be switched between different speeds of air pressure, and long press the button for 3 seconds, the exact battery level and speed of the actual working time. Serves as a low battery reminder to remind you to charge this portable fan in time Fast Cooling & Removable Fan Guard: The USB fan has a 5-blade design that maximizes airflow for a cooler, softer breeze. In addition, the fan guard has an extra guarantee that it can be used to clean the fan and prevent any allergies caused by dust accumulation. Low noise and portability: The high-quality pure copper motor effectively reduces friction noise and provides strong wind with less noise. The USB rechargeable fan weighs only 190g and can be easily and quickly carried around