Not burn out while it is short circuited. There is anti-short circuit be planted in the flash device.

Not burn out in the water for long time. We all choose the waterproof and acid proofing components to prevent  our flash devices being burn out.

Not burn out while it is loaded high voltage. There is anti-overvoltage circuit be planted in the flash device.

Not burn out while it is over loaded. There is anti-overload circuit be planted in the flash device.