Your search for "10310" revealed the following:

NEW Extreme 10310 10GB BASE-ZR 1550nm SMF LC SFP+ Transceiver

SKU: NSN-5918
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Extreme 10310 10GB BASE-ZR 1550nm SMF LC SFP+ Transceiver

SKU: NSB-4885
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days