【Charging function】 We provide a USB charger to save you the trouble of buying batteries. The device can be easily turned on/off using the power switch. The volume can be easily adjusted by just touching the button without any tools. And he can be charged anywhere there is a USB socket, such as company computers, home sockets, etc.【Lasts all day】: Time to upgrade your and forget about always running out or changing batteries. Now the Energy efficient rechargeable batteries gives you longer battery life and use between charges. Without changing batteries all the time you will be free to do the things you love【Charging Box】Machines can be fully charged within 30 minutes and can reach an ultra-long standby time of 6 hours after being fully charged. .