Your search for "QSFP28" revealed the following:
NEW Dell S4128F-ON 210-ALSY 28x 10GB SFP+ 2x 100GB QSFP28 F-B Air OS10 Switch
SKU: NSN-2200
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4148T-ON-RA 48x 10GB Copper 2x 40GB QSFP+ 4x QSFP28 B-F No OS10 Switch
SKU: NSB-9789
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Juniper JNP-100G-4X25G-3M 3m 100GB QSFP28 to 4x 25GB SFP+ Breakout Cable
SKU: NSN-4749
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Juniper QFX5200-48Y-DC-AFO 48x 25GB SFP28 6x 100GB QSFP28 F-B Air (DC) Switch
SKU: NSH-8259
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Dell S4112T-ON 12x 10GB Copper 3x 100GB QSFP28 F-B Air AC (No OS10) Switch
SKU: NSB-9779
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW nVidia Mellanox MCX515A-CCAT ConnectX-5 1x 100GB QSFP28 PCIe3.0 x16 NIC
SKU: NSN-1093
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Juniper QFX5120-32C-AFI 32x 100GB QSFP28 Back-to-Front Airflow Switch
SKU: NSH-9464
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Dell N3248PXE-ON 48x 10GB PoE Copper 4x SFP28 2x QSFP28 F-B Air OS6 Switch
SKU: NSN-9977
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Dell S4148T-ON 48x 10GB Copper 2x 40GB QSFP+ 4x 100GB QSFP28 F-B OS10 Switch
SKU: NSH-9212
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Cisco N9K-C9364C Nexus 9000 64x 100GB QSFP28 2x 10GB SFP+ B-F Air Switch
SKU: NSN-0366
Condition: New
Shipping: Overnight Options
Warranty: 365 days