Hi,   You can refer to this document: [URL] to check the compatibility SFP for your switch and also the part number for your reference in case you need to purchase.   S4148 support both 10G SFP and 1GSFP RJ45. You can refer to the port profiling at page 223: [URL]   Let me know if this answers your query.   
I do apologize for this trivial question as I get to understand more about optics over copper. I was curious if one were to implement the S4148FE-ON, one could use a mix mix of optic cables as well as SFP+ Transceiver to RJ45 over preexisting copper lines that are CAT6A Also, could one use 1GBase-T SFP RJ-45 Copper Module as well to accommodate older parts of a network. Thanks a bunch with any references. Regards
DELL S4148FE-ON 10GbE SFP+