: An "extra quality" .mp4 file generally implies a high bitrate, often utilizing the H.264 or H.265 (HEVC) codec to preserve skin textures and lighting details that lower-quality streams might compress away.
: SONE-184 is a unique alphanumeric code assigned by the production studio (or S1 No. 1 Style) to identify a specific release. sone184mp4 extra quality