Your search for "qsfp28" revealed the following:

NEW Ruckus Brocade ICX7650-48F 24x 1GB SFP 24x 10GB SFP+ 4x 40GB QSFP+ Switch

SKU: NSN-7964
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Nvidia Mellanox MSX6025T-1SFS SX6025 36x 40GB QSFP FDR10 B-F Air (P2C) Switch

SKU: NSB-2856
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Cisco EPA-QSFP-1X100GE ASR 1000 Series 1x 100GB QSFP100 Router Port Adapter

SKU: NSH-9307
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Juniper EX4400-48T-AFI 48x 1GB RJ-45 1x Expansion Module Slot B-F Air Switch

SKU: NSB-7904
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Juniper EX4400-48T-AFO 48x 1GB RJ-45 1x Expansion Module Slot Switch

SKU: NSB-7902
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days