Flywheel (Legacy) hosts the older Flywheel library builds (below 0.6.9), kept available so that old releases of mods such as Create still work. Newer Flywheel versions are bundled inside the mods that need them, so you only grab this one for legacy setups.
Files cover Forge on Minecraft 1.16.3 - 1.19.2. Running an older Create version on your Minecraft server? Drop this dependency in with one click from the panel.