When you download a Framestor remux, you typically get plus supporting files:

A "remux" is a bit-for-bit copy of the video and audio tracks from a physical Blu-ray or Ultra HD Blu-ray disc. Unlike an "encode," which compresses the video to save space, a remux retains 100% of the original data. FraMeSToR is the name of the release group—an elite collective of internal encoders and rippers known for their rigorous quality standards and meticulous attention to detail. Why FraMeSToR is the Gold Standard

: They provide a 1:1 copy of the source video and audio with zero compression.