DannerDANNER MANUFACTURING 12756 Pondmaster Replacement Impeller for Pump Model 12B, 12756

Hello ,i bought these pump pondmaster 02722 1200 gph magnetic-drive utility pump ,does it fit ?

What is warranty

Pump quit working & upon taking it apart I see the magnetic rotor is split in two; However, pics here shows that is normal?

I notice one of the reviews indicates a plastic shaft. Is it plastic or ceramic? Thanks