Aweek Portable Multifunctional Desk Fan Rechargeable Table Mini Fan with 4 Wind Speeds Adjustable For PC Computer Desktop Home Office Car Wind strong and durable Built-in battery (Black) 4 modes adjustable; High winds and long life ;Perfect fan for the office, home, dorm, study, library, games room,car. Charging:Rechargeable built-in 18650 Li-ion battery,with usb charge cable , versatility, can be used circularly, low cost. 4 speeds:low-middle-high-super high,with working indicator ,small size, light weight, easy to carry travel and outdoor sports. High efficient and 2-8 Hours long working time (Depend on the mode you use), exceptionally long using time and strong power output. The integration design, simple appearance, solid structure, it is realize the huge wind capacity fan portable, more confidence in the transport and using.