Your search for "QSFP28" revealed the following:

NEW Cisco C9500-32C-E Catalyst 9500 32x 100GB QSFP28 Front-to-Back Air Switch

SKU: NSN-3657
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Juniper PTX10001-20C-AO PTX Series 20x 100 Gigabit QSFP28 Router

SKU: NSH-9733
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Juniper QFX5110-48S-DC-AFO 48x 10GB SFP+ 4x 100GB QSFP28 F-B Air (DC) Switch

SKU: NSH-8243
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Chelsio T62100-LP-CR 2x 100GB QSFP28 Host Bus Adapter

SKU: NSB-0878
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell N3224F-ON-RA 24x 1GB SFP 4x 10GB SFP+ 2x 100GB QSFP28 B-F OS6 Switch

SKU: NSN-9975
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Dell Z9264F-ON-RA EMC Z-Series 64x 100GB QSFP28 Back-to-Front Air OS10 Switch

SKU: NSB-7049
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Nvidia Mellanox MCP1600-C01AE30N 1.5m 100GB QSFP28 Direct Attach Cable

SKU: NSN-8574
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

Extreme 7520-48YE-8CE-AC-F 48x 25GB SFP28 8x 100GB QSFP28 F-B Air MACsec Switch

SKU: NSB-9982
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Cisco NCS-5011 NCS 5000 Series 32x 100GB QSFP28 Router

SKU: NSN-9605
Condition: New
Shipping: Overnight Options
Warranty: 365 days