Your search for "QSFP28" revealed the following:
NEW Dell S5296F-ON-RA 96x 25GB SFP28 8x 100GB QSFP28 B-F Air (With OS10) Switch
SKU: NSN-8139
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4128T-ON-RA 28x 10GB 2x 100GB QSFP28 B-F Air 210-ALTI (No OS10) Switch
SKU: NSN-9925
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco QSFP-100G-SM-SR 100GB BASE-CWDM4 1331nm Lite SMF QSFP28 Transceiver
SKU: NSN-2060
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S5224F-ON 24x 25GB SFP28 4x 100GB QSFP28 Front-to-Back Air No OS10 Switch
SKU: NSB-9766
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4128F-ON-RA 210-ALTF 28x 10GB SFP+ 2x 100GB QSFP28 B-F Air OS10 Switch
SKU: NSN-8121
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Juniper JNP-100G-DAC-1M 1m 100GB QSFP28 Direct Attach Copper Cable
SKU: NSN-5681
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5224F-ON 24x 25GB SFP28 4x 100GB QSFP28 Front-to-Back Air OS10 Switch
SKU: NSN-3887
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S5224F-ON 24x 25GB SFP28 4x 100GB QSFP28 Front-to-Back Air OS10 Switch
SKU: NSH-9621
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5148F-ON-RA 210-ANCL 48x 25GB SFP28 6x 100GB QSFP28 B-F OS10 Switch
SKU: NSN-9953
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5224F-ON 24x 25GB SFP28 4x 100GB QSFP28 F-B Air No OS10 Switch
SKU: NSN-9948
Condition: New
Shipping: Overnight Options
Warranty: 365 days