This circuit is an innovative design for dynamic electronics. After being powered on, the thumb like pattern composed of 81 LEDs presents various flashing effects. Press button S2 to adjust the water speed. The products which are suitable for electronic enthusiasts to study and repair circuits. The installation of the circuit requires the buyer to have experience in the circuit. Note: This is DIY kit, not a finished product. You need to solder it yourself. Installation precautions: All light-emitting diodes and microcontrollers have polarity components. Be careful not to install them upside down. If you need other colors or colorful effects, just replace the LED., Weight: 0.10802650838 Pounds, Manufacturer: Aboiled