Feature: 1. Requires that players have certain HIFI experience, and the level of HIFI equipment should not be too low 2. Able to hear and distinguish the tonal changes brought about by different cables on the same system 3. Recommended to buy two sets of trial for better results, which will bring you a comfortable experience 4. The power supply voltage is DC5V, current for 0.5A or more, which is extremely low frequency pulse 5. 7.83HZ wave generator come with stable structure, excellent performance and long service life Specification: Item Type: Schumann Wave Generator Size(LxW): Approx. 120 x 80mm / 4.7 x 3.1in Power Supply: Voltage DC5V, current 0.5A or more. Package List: 1 x Module1 x Line6 x Plastic Board1 x Screw Accessory Kit Note: Please use an independent regulated power supply for each unit to avoid mutual interference between multiple shared power supplies and facilitate independent placement.