The board is 1.5mm thick, 65mm long and 27mm wide. The pads are large, the wires are thick, and the components are beautifully laid out. The circuit uses sound to control 11 LEDs to illuminate water, suitable for assembly, skill training, assembly competition, etc. This kit is a very intuitive display of the functions of the CD4017 and is a suite for learning counters, crossovers, and lantern controllers. At the same time, the kit has great effects, is very interesting and practical, and is also the preferred material for beginners to get started. The circuit board is a glass fiber tin plate Circuit function: 10 LEDs emit light with the sound size and high and low circulating water circulation. The louder the sound, the faster the water flow speed. The L11 flashes once every cycle, which can display the function of 4017 visually.Working voltage: 4V--12V can be, the higher the voltage, the brighter the LED will be.