This item, 458410-B21, is the HPE option part number for the product described as Quad-core Intel Xeon Processor E5450 (3.00 GHz, 80 Watts, 1333 FSB). Further details below.

HPE Option Part #: 458410-B21
HPE Spare Part #: 457878-001
HPE Assembly Part #: 455274-001