This is a switching - mode power supply, operation at input AC voltage 95v to 265v and output DC   voltage of 12v - 20v/4.5A  max 24v/4A with protection function use for various components depending on the machine you are using please use the correct voltage by switching to the right voltage level as indicated if unable to switch please consult a professional before operating this charger as for the damage cause we will not be liable whatsoever to avoid over or under current as it might damage your component dont forget that normal operating temperature and humidity operating temp 0 degrees to 40 degrees Celsius {its normal to generate heat when in operation}humidity 20% to 80%