The LEGO™ LED circuit board is a small PCB compatible with the famous bricks from Denmark that can hold an LED, a current limiting resistor and an optional connector. It is great for adding lighting effects to your constructions. Furthermore, it is 100% customizable.
This kit contains 10 circuit boards, 10 LEDs of different color (red, green, yellow, blue and white, two of each color), 10 current limiting resistors of 390 ohms (good for 5 V power) and 10 current limiting resistors of 820 ohms (good for 9 V power). A 9 V battery clip is in the kit too.