Your search for "DS-C48S-300AC" revealed the following:
NEW Cisco DS-C48S-300AC MDS 9148S Series 300W AC Switch Power Supply
SKU: NSN-5845
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Cisco DS-C48S-300AC MDS 9100 Series 300W AC Switch Power Supply
SKU: NSH-6943
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days