Your search for "qsfp28" revealed the following:

Nvidia Mellanox MSN2700-BS2FC 32x 40GB QSFP28 B-F Air (P2C) Cumulus Linux Switch

SKU: NSB-6743
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MSN2100-BB2RC 16x 40GB QSFP28 F-B Air (C2P) Cumulus Linux Switch

SKU: NSB-6770
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S4112F-ON 12x 10GB SFP+ 3x 100GB QSFP28 F-B Air OS10 Switch

SKU: NSN-9956
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Cisco NCS-5501-SE NCS 5500 40x 10GB SFP+ 4x 100GB QSFP28 Router Chassis

SKU: NSN-9830
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

NEW Arista DCS-7280TR-48C6-R 48x 10GB Copper 6x 100GB QSFP28 B-F Airflow Switch

SKU: NSN-3567
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Fortinet FS-3032E 3000 Series 32x 100GB QSFP28 Front-to-Back Airflow Switch

SKU: NSN-8458
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 Extreme Brocade BR-SLX-9140-48V-AC-R 48x 25 SFP28 6x QSFP28 B-F Air Switch

SKU: NSN-4589
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Mellanox MSN2410-BB2RO 48x 25GB SFP28 8x 100GB QSFP28 F-B Air (C2P) ONIE Switch

SKU: NSB-6760
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days