Your search for "QSFP28" revealed the following:
Cisco N9K-C93180YC-EX-WS 48x 25GB SFP+ 6x 100GB QSFP28 F-B Switch SmartNet Clear
SKU: NSB-3823
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell N3248P-ON-RA 48x 1GB PoE RJ45 4x 10GB SFP+ 2x QSFP28 B-F OS6 Switch
SKU: NSN-9976
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Mellanox MSN2410-CB2F 48x 25GB SFP28 8x 100GB QSFP28 B-F (P2C) Onyx Switch
SKU: NSN-9826
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
Nvidia Mellanox MSN2100-CB2FO 16x 100GB QSFP28 B-F Air (P2C) ONIE Switch
SKU: NSB-6766
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Arista AOC-Q-Q-100G-5M 5m 100GB QSFP28 Active Optical Cable
SKU: NSB-5265
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN2010-CB2FC 18x 25GB SFP28 4x QSFP28 B-F CL Switch
SKU: NSN-4796
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN2700-CS2FC 32x 100GB QSFP28 B-F Air Cumulus Linux Switch
SKU: NSN-0210
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 Arista DCS-7280CR2K-30-F 7280CR Series 30x 100G QSFP28 F-R Airflow Switch
SKU: NSN-3664
Condition: New
Shipping: Overnight Options
Warranty: 365 days