This is a 4 pack of 0402 0.8mm pre-wired Red SMD LED.

Includes a 1k resistor. Rated from 3 to 12 volts with appropriate resistor. For 6 to 12 volts i would use a 10k resistor.

These LEDs can be very sensitive so would start with a higher value resistor and work down till you reach an acceptable light level.

Suitable for marker lights in locos and wagons. Can be used with DCC decoders. Remember to use a resistor.