Question about HP Elite Tower 800 G9

The power supply for this PC is not only 260W; it can come with a 260W internal power adapter, but there are also options for 400W and 550W internal power supplies available. The 260W internal power supply is standard, but HP offers a 400W internal power supply (part number 942332-001) and a 550W internal power supply (part number M86264-001) for higher power needs.