You can find the 2021 remaster in several digital tiers on the Official Metallica Store :

: Includes the remastered album plus two additional "discs" of content featuring unreleased demos, rough mixes, and live recordings from the "Wherever We May Roam" tour.

: The high-res 24-bit FLAC files reveal deeper low-end sub-frequencies (20-32Hz) and crisper high-end detail in cymbals and acoustic textures, such as the sitar intro in "Wherever I May Roam". Vocal Clarity