Check the listing for details. Schumann Wave Resonance Generator, Frequency Healing Devices, Frequency Generato. Condition: New. Listed at 37.69 USD. 【Compact, Portable, and Silent Design】 Designed with a compact 15x15cm PCB board, this resonance generator is lightweight and easy to carry. 【Adjustable Frequency for Brain Wave Synchronization】 Our wave generator features an adjustable frequency range from 0.01Hz to 100,000Hz, covering all major brain wave frequencies: δ wave (0.5 - 3.5Hz) for sleep, θ wave (4 - 7Hz) for relaxation, α wave (8 - 13Hz) for calmness, and β wave (14 - 30Hz) for focus.【Compact, Portable, and Silent Design】 Designed with a compact 15x15cm PCB board, this resonance generator is lightweight and easy to carry. 【Adjustable Frequency for Brain Wave Synchronization】 Our wave generator features an adjustable frequency range from 0.01Hz to 100,000Hz, covering all major brain wave frequencies: δ wave (0.5 - 3.5Hz) for sleep, θ wave (4 - 7Hz) for relaxation, α wave (8 - 13Hz) for calmness, and β wave (14 - 30Hz) for focus.