The NC930 is a mains to regulated DC power supply providing 250mA at 13.5V. The green 'ON' indicator indicates that the unit is powered up. Features A compact 12V 250mA double gang power supply unit. Can provide power to up two NC944 Four Zone Call Controllers. Suitable for use in many other applications. Includes a green power on indicator Optional NC941B 12V 0.3Ahr battery back-up kit also available to ensure the NC930 remains operational in the event of Mains failure. Mounts on a standard UK 25mm double gang flush or surface back box.