Your search for "10504" revealed the following:
Extreme 10504 25GB BASE-LR 1310nm SMF SFP28 Transceiver
SKU: NSB-7635
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 306.99
• Only 2 remaining
Call if you need more
HPE JC751A FlexNetwork 10504 Series Switch 640Gbps Type B Fabric Module
SKU: NSB-3841
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 734.99
• Only 2 remaining
Call if you need more
NEW HPE JC751A FlexNetwork 10504 Series Switch 640Gbps Type B Fabric Module
SKU: NSN-3511
Condition: New
Shipping: Overnight Options
Warranty: 365 days