xt480 I/O module options & part numbers

Hi, 

Looking to get a 4-port 10Gb SFP+ SLIC for a Unity xt480, but it seems like that might not be supported on this generation of Unity (p/n 303-410-001B).  I do see there's a 25Gb option but I can't find a part number for it anywhere.  Can anyone help?

Thanks,