WikiLeaks is releasing Vault 7 at 9 a.m. Eastern tomorrow, but they’ve already provided a link for people in the public to download a torrent file that they can then “unpack” using 7Zip. Rumors have been circulating the Internet about what Vault 7 could be, but no one is really sure yet. But what is 7 Zip? We do know that.

Here’s what you need to know.

7z isn’t anything that confusing, even thought WikiLeaks refers to it in their tweets. In fact, it’s a commonly known program. It refers to 7 Zip, a program used to unarchive files.

7-Zip is an open source utility used to compress or unpack archived files. It uses its own archive format called 7z, but the program can also read other archive formats too. Apparently WikiLeaks prefers the 7z archive format and used that for their latest release. 7-Zip is what you will need to open WikiLeaks’ Vault 7 file. However, you’ll also need WikiLeaks’ passphrase, released tomorrow at 9 a.m. Eastern, to finish the process and read the file.

To find 7-Zip programs, just search for 7-zip on Google. A particularly popular one is here.

To open a 7z file on a Mac, WikiLeaks recommends this program: