Overflow Custom Firmware
The Custom Firmwares are packed into a .zip file.
When the CFW is downloaded, launch MultiMAN and go into the File Manager (mmOS).
Now, all you need to do is a double click on the .zip File downloaded (PS3~dev_usb000.zip).
Select 'YES' to the question.
It will extract the 'PS3/UPDATE/PS3UPDAT.PUP' directory ready for the new CFW installation :)
Overflow 4.85 Standard CEX
Overflow 4.85 Dualboot
Overflow 4.85 COBRA 8.01
Overflow 4.85 COBRA 8.01 NoBD
Overflow 4.85 COBRA 8.01 NoBT