Round button design, one key to turn on, adjust power. Fall asleep every day USB charging is convenient, can be connected to the computer's USB port, mobile power, power supply and other charging methods, and the battery life is long. The use of this product can stimulate the neurotransmitter of the cerebral through -current to regulate emotions, thereby promoting sleep. Using this product, the hands can be properly stimulated, so that the same hand and brain frequencies can be used to relieve anxiety. Small and convenient, you can take it with you.Suitable for people with insomnia, overthinking, etc. Specification: Input voltage: DC 5V/1A Battery capacity: 500mAh Working power: 0.5W Working current: 1.5-2A Charging time: 1.5H Product material: ABS+stainless steel Product size: 25 x 32 x 70mm Effectively help you fall asleep and improve their sleep quality. Color: Gray Package Contents: 1 x Help sleep 1 x USB data cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.