Your search for "QSFP28" revealed the following:

NEW Juniper QFX5110-48S-DC-AFI 48x 10GB SFP+ 4x 100GB QSFP28 B-F Air (DC) Switch

SKU: NSN-3622
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MSN2010-CB2F 18x 25GB SFP28 4x QSFP28 B-F Air (P2C) Onyx Switch

SKU: NSB-6773
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Arista CAB-Q-Q-100G-3M 3m 100GB QSFP28 Direct Attach Copper Cable

SKU: NSN-6757
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Dell S4148FE-ON-RA 48x 10GB SFP+ 2x 40GB QSFP+ 4x QSFP28 B-F No OS10 Switch

SKU: NSB-9791
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Arista DCS-7500R2A-36CQ-LC 7500R Series 36x 100GB QSFP28 Switch Line Card

SKU: NSN-9200
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Arista DCS-7280CR2K-30-F 7280CR Series 30x 100G QSFP28 F-R Airflow Switch

SKU: NSN-3664
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Cisco N3K-C34180YC 48x 25GB SFP+ 6x 100GB QSFP28 Back-to-Front Air Switch

SKU: NSN-8251
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Mellanox MSN2410-BB2RO 48x 25GB SFP28 8x 100GB QSFP28 F-B Air (C2P) ONIE Switch

SKU: NSB-6760
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S5232F-ON EMC S 32x 100GB QSFP28 2x 10GB SFP+ F-B Air No OS10 Switch

SKU: NSN-9942
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Juniper PTX10K-LC1101 PTX 10000 Series 30x 100G QSFP28 Router Line Card

SKU: NSH-9738
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days