Two Nb3Sn cable-in-conduit conductors have been procured for Se.C.R.E.T.S. (Segregated Copper Ratio Experiment on Transient Stability), The two conductors are identical in the fractional cross sections. The only difference is the location of the copper stabilizer, included either as segregated copper wires or as a copper shell in the superconducting strands. A number of characterization tests, on individual strands and cabled conductors, have been carried out to establish a solid data base for the assessment of the results in the main experiment.