Your search for "Dell S4820T" revealed the following:
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
Dell S4148T-ON-RA 48x 10GB Copper 2x 40GB QSFP+ 4x QSFP28 B-F No OS10 Switch
SKU: NSB-9789
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S4048T-ON 210-AHMR 48x 10GB Copper 6x 40GB QSFP+ F-B Air OS9 Switch
SKU: NSB-2485
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4128T-ON 28x 10GB 2x 100GB QSFP28 F-B Air 210-ALTC (No OS10) Switch
SKU: NSN-9178
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
Dell S4048T-ON-RA 210-AHMV 48x 10GB Copper 6x 40GB QSFP+ B-F Air No OS10 Switch
SKU: NSB-9785
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S5248F-ON-RA 48x 25GB SFP28 2x 200GB QSFP28-DD 4x QSFP28 B-F OS10 Switch
SKU: NSB-6590
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4048T-ON 210-AHMR 48x 10GB Copper 6x 40GB QSFP+ F-B Air OS10 Switch
SKU: NSN-1874
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148FE-ON 48x 10GB SFP+ 2x 40GB QSFP+ 4x QSFP28 F-B Air OS10 Switch
SKU: NSN-1909
Condition: New
Shipping: Overnight Options
Warranty: 365 days