I believe that is one of the EVGA "SuperNova" series PSU's. I could find nothing about their lower wattage units... what does the label say for how many +12V rails (they all seem to have multiple rails) and the amperage for each rail? Does the PSU have the 2 PCIe connectors needed for the 560ti?
There is also another possible PSU, there is a brand of PSU called NOX, they do have a 450W PSU (although I can find no reviews for it) which seems a little more likely here... on the 12v rails (there's a label on one of the sides that has this information) does it say 12v1 and under that have 16A and 12v2 have 17A?