Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si Hand-operated AC and DC generator: a teaching instrument, simple to operate, highly practical, and meticulously crafted. Intuitive demonstration, good verification, turning boring text into experiments, is a good helper for understanding, learning and interesting teaching. Meticulous craftsmanship, smooth edges, stable base. Product name:Hand cranked AC and DC generator Product features:easy to use, stable performance, intuitive demonstration, easy to operate Scope of application:Mainly used in middle school physics teaching demonstration laboratories, and can also be used by colleges and universities, scientific research institutions, electronic product manufacturers and maintenance units Colour:As Shown Material:Metal+Plastic+Wood+Magnet Size:29x18cm Package Contents: 1 * hand generator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.