Fangrui Product Details Stable And Reliable - Ensures Stable Frequency Output With Default 7.83hz And Voltage Amplitudes Of 3v For Sinusoidal And 5v. Multiple Waveforms - Provides Sinusoidal, And Inverted Options For Versatile Applications. Promote Relaxation And Well Being - Emits A Sinusoidal That Creates A Relaxing Environment. Advanced Specifications - Powered By A Usb Interface And Boasting A Frequency Of 7.83hz, Our Schumann Generator Is Less Than 1w Of Rated Power, Which Ensures Efficient Utilization Of Energy. Compact And Convenient - Compact Size Of 10.2x8.1cm And Usb Powered For Easy Carrying And Use At Home Or While Traveling. For The Bedroom To Help Sleep Soothe The Nerves, Treatment Of Insomnia. For The Office Relax And Improve Work Efficiency. For The Leisure Time Resting Body And Mind. Colour:as Shown Material:pcb Package Contents: 1 * Pulse Generator(not A Finished Product, Needs Assembly) Only The Above Package Content, Other Products Are Not Included. Note: Light Reflection And Different Displays May Cause