Features 7.8HZ SCHUMANN WAVE GENERATOR: Do not directly affect sound or video products to enhance sound and image quality, but acts on the spatial environment, providing specific frequencies of electromagnetic waves. EASY TO USE: Schumann wave generator itself does not emit any sound. Simply plug it in and use it. No need to connect it to any other device. MAIN EFFECTS: The use of Schumann wave generator enhances relaxation, concentration, and overall well being by creating a harmonious sonic environment. NEUTRALIZING RADIATION: Supports a healthy, stress free living environment by neutralizing harmful electromagnetic radiation and promoting a more balanced and calm state of being. PERFECT GIFT: Schumann wave generator is perfect gift choice for friends and family that suffer from insomnia and mental stress. Specification: Item Type: Schumann Wave Generator Material: PCB Resonant Frequency: 7.8HZ(adjustable) Indicator Light: Breathing light indicates operation, can assist sleep Package List:1 x Schumann Wave Generator Note:No battery can not be charged, connected to the USB cable power supply. Package List 1 x Schumann Wave Generator