Your search for "qsfp28" revealed the following:

NEW Mellanox MSB7700-ES2F SB7700 Infiniband 36x 100GB QSFP28 EDR B-F Air Switch

SKU: NSN-0627
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Arista DCS-7800R3-48CQM-LC 48x 100GB QSFP28 w/ MACsec Router Line Card

SKU: NSB-0973
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

HPE JL722C Aruba CX 8360 v2 Series 24x 10GB SFP+ 2x 100GB QSFP28 Switch

SKU: NSB-3811
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW HPE Aruba JL625A 48x 25GB SFP28 8x 100GB QSFP28 Back-to-Front Airflow Switch

SKU: NSN-3640
Condition: New
Shipping: Overnight Options
Warranty: 365 days

EdgeCore 7712-32X-O-48V-B AS7712-32X 32x 100GB QSFP28 B-F Airflow (DC) Switch

SKU: NSB-0622
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Cisco N540-24Z8Q2C-SYS 24x 10GB SFP+ 8x 25GB SFP28 2x 100GB QSFP28 Router

SKU: NSB-8195
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell N3248P-ON 48x 1GB PoE RJ45 4x 10GB SFP+ 2x 100GB QSFP28 F-B OS6 Switch

SKU: NSN-9973
Condition: New
Shipping: Overnight Options
Warranty: 365 days

EdgeCore AS5916-54XM-O-48V-F 48x 10GB SFP+ 6x 100GB QSFP28 F-B Air (DC) Switch

SKU: NSB-2313
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MSB7800-ES2R 36x 100GB QSFP28 F-B Airflow (C2P) Switch

SKU: NSB-6782
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MSN2010-CB2FC 18x 25GB SFP28 4x QSFP28 B-F Cumulus Linux Switch

SKU: NSB-6775
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days