1. The Schumann wave generator produces extremely low-frequency electromagnetic waves. The wavelength of 7.83Hz is approximately 38,000 kilometers, close to the Earth's circumference. The Earth and the ionosphere form a natural electromagnetic resonant cavity, with 7.83Hz being its natural frequency. Emitting electromagnetic waves at this frequency can create standing waves in Earth's space, oscillating continuously for a long time. 2. Operating mode: 7.83Hz extremely low-frequency electromagnetic wave, close to a faint, audible odd harmonic. Power: Low setting 60mW, High setting 180mW. Battery life: Low setting 7 days (no blue light flashing), High setting 2 days. 2000mAh lithium battery, Type-C charging, compatible with mobile phone chargers. 3. Natural Schumann waves are multi-spectral composite waveforms; a simple 7.83Hz sine wave cannot reconstruct them. A 7.83Hz square wave, after Fourier decomposition, consists of the fundamental wave and odd harmonics, including naturally occurring harmonic components. Therefore, the square wave is closer to the natural Schumann wave state. 4. The main electromagnetic background of Schumann wave resonance is in the electromagnetic spectrum from 3 Hz to 60 Hz, with peaks around 7.83 Hz (fundamental wave), 14.3, 20.8, 27.3, and 33.8 Hz. However, this frequency is not constant; it is affected by solar-induced ionospheric disturbances, as well as temperature and humidity. 5. This Schumann wave sound generator has a built-in 2000mA rechargeable battery and supports wireless operation, making it ideal for home, office, or travel. Whether for scientific exploration or daily health management, one device can meet multiple needs.
1. The Schumann wave generator produces extremely low-frequency electromagnetic waves. The wavelength of 7.83Hz is approximately 38,000 kilometers, close to the Earth's circumference. The Earth and the ionosphere form a natural electromagnetic resonant cavity, with 7.83Hz being its natural frequency. Emitting electromagnetic waves at this frequency can create standing waves in Earth's space, oscillating continuously for a long time. 2. Operating mode: 7.83Hz extremely low-frequency electromagnetic wave, close to a faint, audible odd harmonic. Power: Low setting 60mW, High setting 180mW. Battery life: Low setting 7 days (no blue light flashing), High setting 2 days. 2000mAh lithium battery, Type-C charging, compatible with mobile phone chargers. 3. Natural Schumann waves are multi-spectral composite waveforms; a simple 7.83Hz sine wave cannot reconstruct them. A 7.83Hz square wave, after Fourier decomposition, consists of the fundamental wave and odd harmonics, including naturally occurring harmonic components. Therefore, the square wave is closer to the natural Schumann wave state. 4. The main electromagnetic background of Schumann wave resonance is in the electromagnetic spectrum from 3 Hz to 60 Hz, with peaks around 7.83 Hz (fundamental wave), 14.3, 20.8, 27.3, and 33.8 Hz. However, this frequency is not constant; it is affected by solar-induced ionospheric disturbances, as well as temperature and humidity. 5. This Schumann wave sound generator has a built-in 2000mA rechargeable battery and supports wireless operation, making it ideal for home, office, or travel. Whether for scientific exploration or daily health management, one device can meet multiple needs.
Sellers offer a range of delivery options, so you can choose the one that’s most convenient for you. Many sellers offer free delivery. You can always find the postage cost and estimated delivery date in a seller’s listing. You'll then be able to see a full list of delivery options during checkout. These can include: Express delivery, Standard delivery, Economy delivery, Click & Collect, Free local collection from seller.
Your options for returning an item vary depending on what you want to return, why you want to return it, and the seller's return policy. If the item is damaged or doesn't match the listing description, you can return it even if the seller's returns policy says they don't accept returns. If you've changed your mind and no longer want an item, you can still request a return, but the seller doesn't have to accept it. If the buyer changes their mind about a purchase and wants to return an item, they may need to pay return postage costs, depending on the seller's return policy. Sellers can provide a return postage address and additional return postage information for the buyer. Sellers pay for return postage if there's a problem with the item. For example, if the item doesn't match the listing description, is damaged or defective or is counterfeit. By law, customers in the European Union also have the right to cancel the purchase of an item within 14 days beginning from the day you receive, or a third party indicated by you (other than the carrier) receives, the last good ordered by you (if delivered separately). This applies to all products except for digital items (e.g. Digital Music) that are provided immediately to you with your acknowledgement, and other items such as video, DVD, audio, video games, Sex and Sensuality products and software products where the item has been unsealed.
Sellers have to offer a refund for certain items only if they are faulty, such as: Personalised items and custom-made items, Perishable items, Newspapers and magazines, Unwrapped CDs DVDs and computer software. If you used your PayPal balance or bank account to fund the original payment, the refunded money will go back to your PayPal account balance. If you used a credit or debit card to fund the original payment, the refunded money will go back to your card. The seller will effect the refund within three working days but it may take up to 30 days for Paypal to process the transfer. For payments funded partially by a card and partially by your balance/bank, the money taken from your card will go back to your card and the remainder will return to your PayPal balance.