If you are looking for this specific release, you are likely encountering an encode. These codecs allow the 1080p Blu-ray data to be compressed into manageable file sizes while maintaining "transparent" quality (quality indistinguishable from the original disc to the naked eye).
The Wire S01-S05 Complete Series 1080p BluRay x264/x265 Repack thewires01s05completeseries1080pblurayx repack