brand new and high quality. Feature: Application: Schumann wave does not directly act on speakers or video products to improve sound quality, but acts on the space environment. 7.83Hz Low Frequency: Schumann wave extremely low frequency 7.83Hz offsets the frequency of negative interference from electromagnetic waves. Makes the sound space reverberation stable and harmonious, allowing listeners to enjoy music more concentrated and enjoyable. Advantages: It can improve the human body's perception of sound and images, improve the for health of the human body. Improve the efficiency of work creation, and also have a good effect on insomnia and mental stress. Features: High stability pulse chip, features high accuracy and stability. The durable material ensures its durability, with a long service life. Portable: This Module is lightweight and compact, easy to carry. Specifications: Material: Electronic component Color: As shown Size(LxWxH): About 113x91x23.5mm/4.45x3.58x0.9in Types: 1(No for Case), 2(With for Case) Voltage: DC5V Current: 0.5A or more Note: Transition: 1cm=10mm=0.39inch Please allow 0-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package Includes: 1 x Schumann Wave Generator 1 x USB to DC005 Cable 1 x for Case(Only for type 2) 1 x Installation Accessory Pack