The descent2_3dfx_123.sit file you have requested: Official Patches / Mac / Descent II Patch (Macintosh) - 1.64mb is not available. Perhaps try browsing all files for the game Descent 2 and upload any files you want to share or are missing. This is the only information we could locate:
Takes advantage of 3dfx graphics cards. Must have a full version of Descent II to use it.