RFE for H1B Transfer (Not subject to Cap) - Client Letter and SOW

Hi, My Case is filed under (H1B Transfer - not subject to Cap) on 2019 July.
Now i got RFE asking for Client Letter and SOW.

Please help me out whether we have any alternative for Client Letter.
SOW and Manager Letter is more than enough?

Thanks in advance.

Any answer appreciated :slight_smile: