The 169-10C-120 is a 169 model GE Multilin motor management relay with RTD sensors that are composed of 10 ohm copper, as indicated in the part number order option (10C). The other order options at this locale are 100P, 100N, or 120N. These order options specify RTD sensory composition as 100 ohm platinum, 100 ohm nickel, or 120 ohm nickel respectively. The other features that can be specified in the part number order codes is the control voltage of the relay. In this case, the 169-10C-120 has a 120 AC (120 volts AC), which is indicated by the terminal 120 numeric in the part number. The 169-10C-120 is not a drawout version relay (D/O) and therefore the designations for fail-safe or contact arrangement are not indicated in the part number. The fail-safe code can be field programmable in this case. The 169 only has two locales for the TRIP and the ALARM inputs, which can either be FS (fail safe) or (NFS) not fail safe at each locale with a total of four possibilities.  The 169 Plus models however have two additional locales (AUX 1 and AUX2). Thus, the fail-safe code for the 169 Plus relays have a total of eight possibilities, as each locale can also be designated as FS or NFS. Again, these fail-safe combinations can be field selectable as long as the Multilin 169 or 169 Plus relay is not a D/O version.