The cbp3_volume4_installer.exe file you have requested: Maps Levels Missions / Map Packs / UT3 Community Bonus Pack 4 / Unreal Tournament 3 Community Bonus Pack Volume 4 - 519.27mb is not available. Perhaps try browsing all files for the game Unreal Tournament 3 and upload any files you want to share or are missing. This is the only information we could locate:
The pack features 11 new maps (4 DM, 5 DOM, 1 CTF, 1 WAR) and 2 new pickups! It also includes the Domination gametype again (same as Volume 3).