Your search for "QSFP28" revealed the following:
Dell S5248F-ON 48x 25GB SFP28 2x 200GB QSFP28-DD 4x 100GB QSFP28 F-B OS10 Switch
SKU: NSH-9215
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Extreme VSP7400-48Y-8C-AC-F 48x 25GB SFP28 8x 100GB QSFP28 F-B Airflow Switch
SKU: NSH-8528
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Arista CAB-Q-4S-100G-3M 3m 100GB QSFP to 4x 25GB SFP28 DA Breakout Cable
SKU: NSB-5255
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Arista AOC-Q-Q-100G-5M 5m 100 Gigabit QSFP28 Active Optical Cable
SKU: NSN-5666
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Juniper QFX5200-32C-DC-AFO 32x 100G QSFP28 Front-to-Back Airflow (DC) Switch
SKU: NSH-8255
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Arista AOC-Q-Q-100G-1M 1m 100GB QSFP28 Active Optical Cable
SKU: NSB-5262
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Juniper MPC7E-MRATE-RB MX2000 Series 12x 100GB QSFP28 Router Line Card
SKU: NSB-2701
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell S5248F-ON-RA 48x 25GB SFP28 2x QSFP28-DD 4x QSFP28 B-F No OS10 Switch
SKU: NSN-9941
Condition: New
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
NEW Juniper QFX5120-48Y-DC-AFO 48x 25GB SFP+ 8x 100GB QSFP28 F-B Air (DC) Switch
SKU: NSN-3629
Condition: New
Shipping: Overnight Options
Warranty: 365 days