HPYP Electric Portable Mini USB 3-Speeds Personal &Table Fan - 4"nch Vanes Fan with Rechargeable Battery and USB Charge Cable (Black) A professional portable mini fan with integration of design, simple appearance and firm structure, LED lighting three gear speeds to meet your need High efficient and 2-7 Hours long working time-Depend on the mode you use Different ways to charge fan with lithium battery in: connect micro USB charging cable via computer/notebook, car charger, power bank, 5V wall USB charger, 5v solar charger etc. Indoor use when need instant cooling need for kitchen and bedroom, saving power when air condition is not so necessary. Especially perfect for outdoor activities and travel. International standard 18650 capacity lithium battery provides exceptionally long using time and strong power output.