Your search for "qsfp28" revealed the following:
NEW Extreme Brocade BR-SLX-9140-48V-AC-F 48x 25GB SFP28 6x QSFP28 F-B Air Switch
SKU: NSN-3852
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Mellanox MSN2100-BB2FC 16x 40GB QSFP28 B-F Airflow (P2C) Cumulus Linux Switch
SKU: NSB-6769
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
HPE Aruba JL704C 44x 25GB SFP28 6x 100GB QSFP28 F-B Airflow Switch w/ MACsec
SKU: NSB-9590
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Extreme SLX9250-32C-AC-R SLX 9250 32x 100G QSFP28 B-F Air Switch
SKU: NSH-9999
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Extreme VSP7400-32C-AC-F VSP 7432CQ-F 32x 100G QSFP28 F-B Airflow Switch
SKU: NSH-8499
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN3700-CS2FC 32x 100GB QSFP28 B-F Cumulus Linux Switch
SKU: NSN-9999
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Ruckus ICX7850-32Q-E2 ICX 7850 Series 32x 100GB QSFP28 Switch
SKU: NSB-6342
Condition: Seller refurbished
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
Nvidia Mellanox MSN4600-CS2FC 64x 100GB QSFP28 B-F Air P2C Cumulus Linux Switch
SKU: NSB-6709
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MMA1L30-CM 100GB 1310nm SMF 2km DOM QSFP28 Transceiver
SKU: NSN-8604
Condition: New
Shipping: Overnight Options
Warranty: 365 days