These small LEDs are known as surface mount LEDs, SMD LEDs, or Chip LEDs. They are very small and compact yet very bright!. The benefit of a flat and compact LED chip is that it still fives a great amount of light, but can be mounted flush, with no bulb shape showing.
The chip LED assembly is wired with a 14 inch red/green superfine magnet wire as the main lead from the LED. Connect the main lead using the screw terminal posts on the terminal block and plug-in either the 3V battery supply or the AC/DC/DCC rectifier assembly to the other side of the terminal block.
1 - prewired warm white CHIP LED
1 - 2-Pos pluggable terminal block
1 - 3v Battery Assembly (3V CR2032 battery, battery holder, and push button switch)
1 - 7-19v AC/DC/DCC rectifier assembly
For more types of LEDs, see our friends at Model Train Software