A 3mm red LED is a type of light-emitting diode (LED) that is 3mm in diameter and emits red light. LEDs are known for their energy efficiency, long lifespan and low power consumption compared to traditional incandescent bulbs. They are commonly used as indicator lights, in electronic devices and displays, automotive lighting, and other applications where a small, bright, and energy-efficient light source is required. The color of the LED is determined by the materials used to create the semiconductor, which can range from red, orange, yellow, green, blue, and white.

These red LEDs will provide your projects will light, instantly! Whether you need to indicate activity in your circuit or simply want to visual effects to your project, LEDs are simple to use and cheap to purchase!

Remember to never plug any LED directly to the power supply or it will destroy it! Ensure that the current through the LED is never more than 20mA. The easiest way to do this is to simply add a resister in series with the LED to reduce the Current to below 20mA. For example, if you have a power supply of of 4.5V then you would need to add a resistor of at least 50 Ohm to ensure the LED has less than 20mA of Current going through it.