Your search for "mmb8500" revealed the following:
Mellanox MMB8500 CS8500 Series Dual Core Switch Chassis Management Module
SKU: NSB-6804
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 6,187.99
• 5 in stock
Call if you need more
NEW Mellanox MMB8500 CS8500 Series Dual Core Switch Chassis Management Module
SKU: NSN-1023
Condition: New
Shipping: Overnight Options
Warranty: 365 days
$ 6,325.99
• 5 in stock
Call if you need more