This specific versioning typically points to an update involving:
Right-click only on Part 01 and select "Extract Here." The software will automatically pull data from Part 02 and the rest of the sequence to rebuild the original full file. Context: Icarus v1.2.12 ICARUS.v1.2.12.100160.part02.rar
If you downloaded this from a non-official source, always run a virus scan on the extracted folder before running any .exe files, as multi-part archives are a common way to distribute modified software. 2.12, or are you having trouble extracting the files? This specific versioning typically points to an update