This is a 1U power supply ATX. This has never been used its just been sitting in a box for a while. This is has ATX power connector for motherboard this would be a good power supply for a new project. You could use this for one of those imac conversion to ATX if you know how to convert the connector to the Imac connection pinouts. I have enclosed pictures of the power supply.
This is the following specs of the ATX power supply:
AC INPUT:115/230V 60/50Hz 6/3A
DC OUTPUT:150W (MAX)
+5V 10A +12V 6A +3.3V 6A
-5V 0.2A -12V 1A +5VSB 720mA