Your search for "qsfp28" revealed the following:
NEW Cisco Meraki MS450-12-HW 12x 40GB QSFP+ 2x 100GB QSFP28 Unclaimed Switch
SKU: NSN-3730
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N9K-C9336C-FX2 36x 100GB QSFP28 Front-to-Back Airflow Switch
SKU: NSN-8187
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S4148U-ON 48x 24x Uni SFP+ 2x QSFP+ 4x QSFP28 F-B No OS10 Switch
SKU: NSN-9962
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4148U-ON 210-ALRZ 48x 24x Unified SFP+ 2x QSFP+ 4x QSFP28 F-B OS10 Switch
SKU: NSH-9214
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S5212F-ON-RA 12x 25GB SFP28 3x 100GB QSFP28 B-B Air No OS10 Switch
SKU: NSB-9769
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Nvidia Mellanox MCP7H00-G002 2m 100GB QSFP28 to 2x 50GB QSFP28 Breakout Cable
SKU: NSB-0915
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S4148U-ON 210-ALRZ 48x 24x Uni SFP+ 2x QSFP+ 4x QSFP28 F-B No OS10 Switch
SKU: NSB-9786
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Amphenol SF-NDAAFF100G-001M 1m 100GB QSFP28 Direct Attach Copper Cable
SKU: NSB-0899
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Cisco N3K-C36180YC-R 48x 25GB SFP+ 6x 100GB QSFP28 B-F Airflow (DC) Switch
SKU: NSH-8368
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Extreme 10423 3m 100GB QSFP28 to 4x 25GB SFP28 Direct Attach Breakout Cable
SKU: NSH-9414
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days