Features Have humanized design, simple operation, easy to install, convenient to use and operate. Small in size and light in weight, convenient to carry and use at any time, very convenient and practical. Have a nice appearance with the simple but elegant design, offer aesthetic satisfaction. Made of high‑quality material, with sturdy and durable quality, have a long service time. Can improve air problems and remove formaldehyde, with good product compatibility. Specification: Item Type: Schumann Wave Generator Product Size: Approx. 102 x 80mm / 4 x 3.1in Power Supply: Voltage DC5V, current 0.5A or more  Package List: 1 x Schumann Wave Generator 1 x Cable Note: Please use an independent regulated power supply for each unit to avoid mutual interference between multiple shared power supplies and facilitate independent placement. Package List 1 x Schumann Wave Generator 1 x Cable