The filename refers to the second part of a multi-volume RAR archive for " That Time I Got Reincarnated as a Slime " (Tensei Shitara Slime Datta Ken) , specifically Season 3, Episode 1 (S01 often refers to the season index in specific release groups, or in this case, likely a typo/internal tag for Season 3, Episode 49 or similar "Season 3" content).
: Right-click Part 1 and select "Extract Here" using WinRAR or 7-Zip . It will automatically pull data from Part 2. TTJDS01WEB4K9.part2.rar
: .rar (Part 2 of a split archive). You need all parts (Part 1, Part 2, etc.) in the same folder to successfully extract the video file. Video Quality : 4K UHD (2160p) WEB-DL. The filename refers to the second part of
: Anime - That Time I Got Reincarnated as a Slime (Season 3). : Anime - That Time I Got Reincarnated as a Slime (Season 3)