Question about Ajax Systems KEYPAD WRL TOUCHSCREEN/ASP BLACK 58454

The device is supplied with power via an external 12V DC power supply unit. There are two connection terminals behind the holder to which the power supply unit is connected directly - plus (+) and minus (-) are labelled accordingly. I have found a suitable power supply unit for you, the cable of which already has open ends and can therefore be fitted directly into the connection terminals. Please pay attention to the correct polarity when connecting: plus to plus, minus to minus. In addition, the keypad has an integrated battery operation, which serves as an emergency power supply if no mains adapter is connected or the power supply is interrupted.