1. Using this product can stimulate neurotransmitters in the cerebral cortex through micro currents, thereby regulating emotions and promoting sleep. 2.Small and convenient, you can carry it with you. 3. The battery capacity is 300mAh, USB is convenient for charging, it can be connected to the computer's USB port, mobile power, power supply and other charging methods. 4..Suitable for people with insomnia, overthinking, etc. Specification: Prouct material :ABS Product size: 40.5*38.5*68.5mm Input voltage: DC 5V Working power: 0.03W Charging port: USB Charging Package Included: Sleep meter x1 USB Cable x1 User Manualx1 Notes: 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. The specific color of the received goods shall prevail. 2. Due to different manual measurement methods, please allow a slight size difference.