This kit contains 12 super bright 3mm LEDs. They are significantly brighter than the originals. You will need to solder the LEDs into your signal board with the flat side of the LED matched to the flat side of the LED mounting circle printed on the PCB (the same side as the printed text).
The images show the LEDs installed in a housing (not included - this kit is just LEDs). The top two LEDs are replacements; the bottom left LED is an original. The bottom right LED is off.