The jackles_modded_gephyrophobia.zip file you have requested: Maps Levels Missions / Miscellaneous / I to J Titles / Jackle's Modded Gephyrophobia - 6.16mb is not available. Perhaps try browsing all files for the game Halo: Combat Evolved and upload any files you want to share or are missing. This is the only information we could locate:
To install, click on the mirror of your choice, it will give you the option save or open, press save and now you should be in My Computer, now got to Local Disk (C:) and choose program files, then Microsoft games, now its extremely obvious, click on This mod adds several tweaks/changes to the game. For example, shotguns shoot half a dozen rockets, assault rifles shoot Fuel Rod plasma, Turret Warthogs fly, you can walk on walls and take no damage from falls.