Your search for "QSFP28" revealed the following:
NEW Nvidia Mellanox MSN3420-CB2FC 48x 25GB SFP28 12x 100GB QSFP28 B-F CL Switch
SKU: NSN-0686
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4112F-ON 12x 10GB SFP+ 3x 100GB QSFP28 F-B Air No OS10 Switch
SKU: NSN-9958
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Cisco NCS-5501 NCS 5500 48x 10GB SFP+ 6x 100GB QSFP28 Router
SKU: NSB-7539
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Nvidia Mellanox MSN2010-CB2R 18x 25GB SFP28 4x QSFP28 F-B Air (C2P) Onyx Switch
SKU: NSB-6774
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Extreme 17360 X690-48t-2q-4c 48x 10GE 2x 40G QSFP+ 4x 100G QSFP28 Switch
SKU: NSN-5020
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Nvidia Mellanox MSN2100-BB2R 16x 40GB QSFP28 F-B Air (C2P) Onyx Switch
SKU: NSB-6768
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN3700-CS2RC 32x 100GB QSFP28 F-B Cumulus Linux Switch
SKU: NSN-9998
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell Z9264F-ON-RA EMC Z-Series 64x 100GB QSFP28 B-F Air OS10 Switch
SKU: NSN-0188
Condition: New
Shipping: Overnight Options
Warranty: 365 days
EdgeCore 5912-54X-O-48V-B AS5912-54X 48x 10GB SFP+ 6x QSFP28 B-F (DC) Switch
SKU: NSB-1430
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW nVidia Mellanox MSN3700-CS2R 32x 100GB QSFP28 F-B Airflow (C2P) Onyx Switch
SKU: NSN-9639
Condition: New
Shipping: Overnight Options
Warranty: 365 days