This upgrade kit includesĀ the C4 LED with SwitchĀ Assembly needed to upgrade yourĀ existingĀ Stinger LEDĀ or Stinger DSĀ LED to the new C4 LEDĀ Technology.Ā (For original Stinger LED models without C or C4 in the serial number.) The C4 technologyĀ upgrade doublesĀ your Stinger LED's brightness to 350 lumens.