This is a set containing a MCPCB with Samsung 351d 5000k primary leds, Vishay 367nm secondary leds and a Dragon driver with a lower output for the secondary. A standard Dragon driver will burn the UV secondary leds out so make sure to keep this set together until installed. YOU CAN NOT USE AN OPTIC WITH THIS. Optics block UV light so you must build this as a mule. Spacers are available for custom flashlights on this site.