Your search for "QSFP28" revealed the following:

NEW Dell S4148U-ON-RA 48x (24x Unified) SFP+ 2x QSFP+ 4x QSFP28 B-F OS10 Switch

SKU: NSN-8126
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S5224F-ON-RA 24x 25GB SFP28 4x 100GB QSFP28 B-F Air OS10 Switch

SKU: NSN-8136
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Cisco A9K-8X100GE-TR ASR 9000 8x 100GB QSFP28 Router Line Card

SKU: NSN-3446
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Juniper QFX5110-48S-AFI 48x 10GB SFP+ 4x 100GB QSFP28 B-F Airflow Switch

SKU: NSN-3749
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 Juniper JNP-QSFP-100G-CWDM 100GB BASE-CWDM4 SMF QSFP28 Transceiver

SKU: NSN-4927
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Juniper QFX5200-48Y-DC-AFI 48x 25GB SFP28 6x 100GB QSFP28 B-F Air (DC) Switch

SKU: NSH-8258
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Mellanox MCP7H00-G01A 1.5m 100GB QSFP28 to 2x 50GB QSFP28 Breakout Cable

SKU: NSB-0913
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MCP1600-C02AE26N 2.5m 100GB QSFP28 Direct Attach Copper Cable

SKU: NSB-2909
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S4148U-ON-RA 48x 24x Unified SFP+ 2x QSFP+ 4x QSFP28 B-F No OS10 Switch

SKU: NSN-9963
Condition: New
Shipping: Overnight Options
Warranty: 365 days