Your search for "QSFP28" revealed the following:
Arista DCS-7280SR2-48YC6-F 48x 25GB SFP28 6x 100GB QSFP28 F-B Airflow Switch
SKU: NSH-8383
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco NCS-5002 NCS 5000 80x 10GB SFP+ 4x 100GB QSFP28 F-B Airflow Router
SKU: NSN-6562
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Finisar FTLC1151RDPL2 100GB BASE-LR4 1310nm QSFP28 Transceiver
SKU: NSB-1160
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell N3248P-ON 48x 1GB PoE RJ45 4x 10GB SFP+ 2x 100GB QSFP28 F-B OS6 Switch
SKU: NSN-9973
Condition: New
Shipping: Overnight Options
Warranty: 365 days
EdgeCore 7712-32X-O-AC-F-US AS7712-32X 32x 100GB QSFP28 F-B Airflow ONIE Switch
SKU: NSB-1672
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Cisco N3K-C36180YC-R 48x 25GB SFP+ 6x 100GB QSFP28 F-B Airflow (DC) Switch
SKU: NSH-8369
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Cisco C9500-32C-A Catalyst 9500 32x 100GB QSFP28 Front-to-Back Airflow Switch
SKU: NSH-8329
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Nvidia Mellanox MSB7800-ES2R 36x 100GB QSFP28 F-B Airflow (C2P) Switch
SKU: NSB-6782
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Extreme VSP7400-48Y-8C 48x 25G SFP28 8x 100G QSFP28 No Fans No PSU Switch
SKU: NSN-3377
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Extreme 17350 X690-48x-2q-4c 48x 10GB SFP+ 2x 40GB QSFP+ 4x QSFP28 Switch
SKU: NSN-3825
Condition: New
Shipping: Overnight Options
Warranty: 365 days