Your search for "5420F-24T" revealed the following:

NEW Extreme 5420F-24T-4XE 5420 Series 24x 1GB RJ45 4x 10GB SFP+ Switch

SKU: NSN-8531
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Extreme 5420F-24T-4XE 5420 Series 24x 1GB RJ45 4x 10GB SFP+ Switch

SKU: NSB-2422
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days