This is a mini ultrasonic suspension device that can suspend foam balls. The device consists of 1 single-chip microcomputer, 1 driver chip and 2 ultrasonic probes. It is mainly used for students or DIY electronics enthusiasts to learn about ultrasonic standing wave suspension. It does not support controlling the up and down movement of suspended objects. Source code is provided. Working principle: Ultrasonic standing wave suspension is through the ultrasonic transmitting end and the reflecting end (or another transmitting end) There is a certain distance (called the resonant cavity distance), the transmitting wave and the reflected wave (or another sound wave) are continuously superimposed to form a standing wave. The sound wave force on the object at the standing wave node overcomes the and finally achieves the effect of suspension. Input voltage: 5v Power supply current: Less than 100mA Device only, without foam ball It's DIY kits, needs to by yourself. The words may be different due to different factory batches, but it not affect the use Color: blue Material: ABS Package Contents: 1set x ultrasonic suspension parts 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.