Features: Mini and portable in size, convenient to use at anywhere. Adjustable 3 kinds of air speed: just press the switch and then adjust the speed freely. High quality brushless motor: durable and high cooling performance. Built-in 18650 rechargeable battery, charged by Micro USB interface. Multiple charging methods: connect with power bank, computer, power adapter, etc. It is a practical good partnergift for travelers and office workers in summer.