Your search for "QSFP28" revealed the following:

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-X9732C-EX 32x 100GB QSFP28 Switch Line Card

SKU: NSN-1826
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW HPE Q9E63A M-Series SN2010M 18x 25GB SFP28 4x 100GB QSFP28 B-F Air Switch

SKU: NSN-0072
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Nvidia Mellanox MSN2410-BB2F 48x 10GB SFP28 8x QSFP28 B-F Air Onyx Switch

SKU: NSN-9264
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Cisco N3K-C36180YC-R 48x 25GB SFP+ 6x 100GB QSFP28 B-F Airflow (DC) Switch

SKU: NSN-0235
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Fiberstore Q-4S2802 2m 100GB QSFP28 to 4x 25GB SFP28 DAC Breakout Cable

SKU: NSB-9823
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Cisco QSFP-100G-AOC20M 20m 100GB QSFP28 Active Optical Cable

SKU: NSH-8873
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Juniper EX4650-48Y-DC-AFI 48x 25GB SFP28 8x 100GB QSFP28 B-F Airflow

SKU: NSH-8961
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S4148T-ON-RA 48x 10GB Copper 2x 40GB QSFP+ 4x QSFP28 B-F No OS10 Switch

SKU: NSN-9965
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Dell S5232F-ON-RA 32x 100GB QSFP28 2x 10GB SFP+ Back-to-Front Air No OS10 Switch

SKU: NSB-9765
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days