Output 12/24 V DC at 99W The features for the PAC 7A switchable power supply are: High Quality power supply that can switch between 12V and 24V DC outputs The PSUs come in a DIN rail mountable form For battery back-up the following batteries are needed in addition: One 7Ah 12V DC battery is required for a 12V DC PSU Two × 7Ah 12V DC batteries connected in series are needed for a 24V DC PSU