Your search for "finisar ftlx8571" revealed the following:
Finisar FTLX8573D3BTL-TM 10GB BASE-SR 850nm MMF SFP+ Transceiver
SKU: NSB-9914
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
Finisar FTLX8574D3BCL-HD BASE-SR 10 Gigabit 850nm Short Range MMF Transceiver SF
SKU: NSB-8752
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
NEW Finisar FTLX8512D3BCL 10GB BASE-SR 850nm MMF XFP Transceiver
SKU: NSN-7218
Condition: New
Shipping: Overnight Options
Warranty: 365 days
NEW Finisar FTLF8528P3BCV-QL 8GB 850nm Multimode Datacom FC SFP+ Transceiver
SKU: NSN-7799
Condition: New
Shipping: Overnight Options
Warranty: 365 days