Your search for "qsfp28" revealed the following:
Dell S4128T-ON 28x 10GB Copper 2x 100GB QSFP28 F-B Air 210-ALTC OS10 Switch
SKU: NSB-9746
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5296F-ON EMC S 96x 25GB SFP28 8x 100GB QSFP28 F-B Air (No OS10) Switch
SKU: NSN-9938
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4128T-ON 28x 10GB Copper 2x 100GB QSFP28 F-B Air 210-ALTC (No OS10) Switch
SKU: NSH-9211
Condition: Seller refurbished
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 Dell S4128F-ON-RA 210-ALTF 28x 10GB SFP+ 2x 100GB QSFP28 B-F No OS10 Switch
SKU: NSN-9933
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW HPE Q2F24A SN2100M 8x 100 Gigabit QSFP28 Back-to-Front Airflow Switch
SKU: NSN-2448
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
NEW Juniper QSFP-100GBASE-SR4 100GB BASE-SR4 850nm MMF QSFP28 Transceiver
SKU: NSN-4077
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
Dell Q28-100G-ESR4 100GB BASE-ESR 850nm MMF QSFP28 Transceiver
SKU: NSB-5958
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days