The product is .83Hz extremely low -frequency generator. Focus on precision and stability! This model is a charging model, a small portable volume, can be , and with charging cable optimized circuit design, gold -plated launch circuit! Remarks: electronic component. It is recommended to use multiple distribution, and the effect can be more experienced Application:Used for audiovisual space For the bedroom Used for office Used for space Used for tea ceremony, meditation space Product name: Charging model Wave Generator Power: 5V -USB interface charging cable Battery: polymer lithium battery, capacity 850mAh Use time: charging current is 250mA, full 6 hours, the working current is about 7mA, and you can use about 200 hours at full power (168 hours a week) Due to different product batches, the appearance , which does not affect the use Colour:As Shown Material:PC+Plastic Size:68x52x12mm(length, width and height ) Package Contents: 1 x Wave Generator 1 x charging cable 1 x screwdriver 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.