Your search for "N56128" revealed the following:
Cisco N56128-FAN-F Back-to-Front Airflow (Fan Side Intake) Switch Fan
SKU: NSH-6168
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 39.99
• Only 2 remaining
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Cisco N56128-FAN-B Front-to-Back Airflow (Port Side Intake) Switch Fan Module
SKU: NSB-7095
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N56128-FAN-B Front-to-Back Air (Port Side Intake) Switch Fan Module
SKU: NSN-0290
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N56128-FAN-F Back-to-Front Airflow (Fan Side Intake) Switch Fan
SKU: NSN-2453
Condition: New
Shipping: Overnight Options
Warranty: 365 days