Power mode:USB Function:handheld wire control Display mode:LED liquid crystal display Working principle: -current pulse Battery life:more than 12h Built-in battery capacity:1200mAh-2000mAh (inclusive) Product Category:Head Mounted Whether built-in battery:built-in battery Contraindications 1. Do not use with implanted -electrical appliances, such as cardiac pacemakers, It may cause equipment failure or trigger hazards. 2. Do not use this product if you have skin problems such as ear allergies, blisters, peeling, frostbite, etc. 3. Do not use this product in with high humidity such as bathrooms. 4. Do not use this product for purposes other than its intended use. 5. Do not give this product to children under the age of six to avoid personal injury. 6. Do not disassemble, repair or refit this product without authorization. Equipment malfunction or injury may result. 7. Before disposing of the appliance, the battery must be removed from the appliance. 8. When removing the battery, the appliance must be disconnected from the power supply. Batteries should be disposed of safely. Colour:Black Material:ABS Package Contents: 1 Set * Smart Sleep instrument 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.