Your search for "dell s4820t" revealed the following:
NEW Dell S4810P-AC 48x 10GB SFP+ 4x 40GB QSFP+ Front-to-Back Airflow Switch
SKU: NSN-2596
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4810P-AC-R XR65V 48x 10GB SFP+ 4x 40GB QSFP+ B-F Airflow Switch
SKU: NSN-0109
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4148T-ON 48x 10GB Copper 2x 40GB QSFP+ 4x 100GB QSFP28 F-B OS10 Switch
SKU: NSH-9212
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148T-ON 48x 10GB Copper 2x 40GB QSFP+ 4x 100GB QSFP28 F-B OS10 Switch
SKU: NSN-1907
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4148T-ON 48x 10GB Copper 2x 40GB QSFP+ 4x 100GB QSFP28 F-B No OS10 Switch
SKU: NSB-9788
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S4148U-ON-RA 48x (24x Unified) SFP+ 2x 40GB QSFP+ 4x QSFP28 B-F OS10 Switch
SKU: NSB-6545
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148U-ON 48x 24x Unified SFP+ 2x QSFP+ 4x QSFP28 F-B OS10 Switch
SKU: NSN-3864
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148FE-ON 48x 10GB SFP+ 2x 40GB QSFP+ 4x QSFP28 F-B No OS10 Switch
SKU: NSN-9966
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5248F-ON 48x 25GB SFP28 2x 200GB QSFP28-DD 4x 100GB QSFP28 F-B Switch
SKU: NSN-1910
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148U-ON 48x 24x Uni SFP+ 2x QSFP+ 4x QSFP28 F-B No OS10 Switch
SKU: NSN-9962
Condition: New
Shipping: Overnight Options
Warranty: 365 days