Your search for "qsfp28" revealed the following:
NEW Cisco N3K-C3636C-R 36x 100GB QSFP28 Front-to-Back Airflow Switch
SKU: NSN-3564
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4112F-ON-RA 12x 10GB SFP+ 3x 100GB QSFP28 B-F No OS10 Switch
SKU: NSN-9959
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N9K-C9364C Nexus 9000 64x 100GB QSFP28 2x 10GB SFP+ F-B Air Switch
SKU: NSN-9679
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N3K-C36180YC-R 48x 25GB SFP+ 6x 100GB QSFP28 Front-to-Back Air Switch
SKU: NSN-3563
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Nvidia Mellanox MCP1600-C003E30L 3m 100GB QSFP28 Direct Attach Copper Cable
SKU: NSB-0919
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Cisco UCS-FI-6454-U UCS 6454 18x 25G SFP28 2x 100G QSFP28 Fabric Interconnect
SKU: NSB-6665
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MCP1600-C003E30L 3m 100GB QSFP28 Direct Attach Copper Cable
SKU: NSN-8336
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Juniper QFX5200-32C-DC-AFI 32x 100GB QSFP28 Back-to-Front Airflow (DC) Switch
SKU: NSH-8254
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Juniper QFX5110-48S-DC-AFI 48x 10GB SFP+ 4x 100GB QSFP28 B-F Airflow (DC) Switch
SKU: NSH-8242
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S4112T-ON 12x 10GB Copper 3x 100GB QSFP28 F-B Air AC (No OS10) Switch
SKU: NSB-9779
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days