Your search for "QSFP28" revealed the following:

Dell S4128T-ON-RA 28x 10GB Copper 2x 100GB QSFP28 B-F Air 210-ALTI OS10 Switch

SKU: NSB-6541
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Juniper QFX5120-48Y-AFI 48x 25GB SFP28 8x 100GB QSFP28 B-F Airflow Switch

SKU: NSN-3626
Condition: New
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

NEW Dell Q28-100G-BIDI 100GB Bi-Di Short-Reach 150m MMF QSFP28 Transceiver

SKU: NSN-2283
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S4128F-ON-RA 210-ALTF 28x 10GB SFP+ 2x 100GB QSFP28 B-F No OS10 Switch

SKU: NSN-9933
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Dell S5232F-ON-RA 32x 100GB QSFP28 2x 10GB SFP+ Back-to-Front Air OS10 Switch

SKU: NSB-6589
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S5148F-ON-RA 210-ANCL 48x 25GB SFP28 6x 100GB QSFP28 B-F No OS10 Switch

SKU: NSN-8132
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S5296F-ON EMC S 96x 25GB SFP28 8x 100GB QSFP28 F-B Air OS10 Switch

SKU: NSN-1911
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Dell S5248F-ON-RA 48x 25GB SFP 2x 200GB QSFP28-DD 4x QSFP B-F OS10 Switch

SKU: NSN-8138
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Dell S4128T-ON-RA 28x 10GB Copper 2x 100GB QSFP28 B-F 210-ALTI (No OS10) Switch

SKU: NSB-9747
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days