A Keyvault (Or KV for short) is a file that can be found on your console’s hard drive. These files hold your Xbox system’s unique serial number, DVD key, CPU Key, etc.
Using modded software or displaying poor conduct within an online game often results in getting your Xbox 360 banned by Xbox Live. Microsoft does this by accessing the details of your Xbox 360s unique identity/ Keyvault and recording it to stop the owner from accessing the online game and content.
If your Xbox console is banned on your RGH/Jtag, you are simply having the Keyvault KV.Bin file banned from use.
With L321 you can buy another one and swap it with the one currently on your Xbox 360 which effectively gives your Xbox 360 a completely new identity. Once loaded your new KV will allow you access and continue to play the online games as your Xbox console will no longer be recognised as banned.
KVs can last for varying amounts of time before getting banned again. This will be all dependent on if they have been purchased from a good source and not been previously used or banned or if your stealth server is inadequate.
A word of warning though there are unscrupulous suppliers who sell either already used Keyvaults (KV’s) or banned Keyvaults (KV’s) so choosing your supplier is critical. L321 will only sell unbanned and unique new Keyvaults and only use trusted suppliers.
Here is a short video explaining how to unban you’re Xbox and installing a KV (Key Vault)