Your search for "qsfp28" revealed the following:
NEW Arista DCS-7280CR3K-32D4-F 32x 100GB QSFP28 4x 400GB QSFP-DD F-B Air Switch
SKU: NSN-6452
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN2100-BB2F 16x 40GB QSFP28 Back-to-Front Air Onyx Switch
SKU: NSN-9266
Condition: New
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
Cisco N540-ACC-SYS NCS 540 24x 10GB SFP+ 8x 25GB SFP28 2x 100GB QSFP28 Router
SKU: NSB-8197
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
HPE Aruba JL707C 8360-48XT4C v2 48x 10GB RJ-45 4x 100GB QSFP28 B-F Air Switch
SKU: NSB-9704
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Nvidia Mellanox MSN2100-CB2FC 16x 100GB QSFP28 B-F Cumulus Linux Switch
SKU: NSN-0107
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Extreme EN-SLX-9030-48T-4C 48x 10GE Copper 4x 100G QSFP28 No Fans/PSU Switch
SKU: NSN-3681
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Ruckus ICX7850-48F ICX 7850 Series 48x 25GB SFP28 8x 100GB QSFP28 Switch
SKU: NSN-8061
Condition: New
Shipping: Overnight Options
Warranty: 365 days
EdgeCore 7712-32X-O-AC-F-US AS7712-32X 32x 100GB QSFP28 F-B Airflow ONIE Switch
SKU: NSB-1672
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco NCS-5002 NCS 5000 80x 10GB SFP+ 4x 100GB QSFP28 B-F Airflow Router
SKU: NSN-0675
Condition: New
Shipping: Overnight Options
Warranty: 365 days