Diving straight in with but an almost-hidden note that the archetypes herein were created by fans of the game (and may not be completely compatible with the rules) - it's buried in the credits page - we have a collection of forty-three new archetypes. Most are contemporary folk who could easily get swept up in a zombie apocalypse, but there are a few from the Old West and other settings if that is what you are playing. They're useful if you need a character in a hurry (maybe the zombies got your last one and you don't want to spectate for the rest of the session) or maybe to give you ideas for characters if you are wondering what to play. They also make good detailed NPCs if needed. There are also a few new pieces of equipment and rules additions at the end.
Each archetype - neatly provided on a single page, especially useful for PDF users who can print just the page they want - contains a full-length sketch of the character, their game statistics and a delightful in-character monologue that tells you enough about them to be able to get a good feel for that character. If you intend to play one, just about all you need do is supply a name. Naturally, you can tweak them a bit if they are not precisely what you want.
The archetypes are quite diverse - administrative assistants, bomb squad, a hacker, a lunatic who's escaped from the nearest asylum... and many more. Some of the backstories they tell could suggest adventures or even a whole campaign if you are so minded.
The new equipment is based around items that some of the archetypes have with them, providing the extra information that you need to use them in game. Likewise there are new Chi abilities, qualities/drawbacks and so on to explain some of the entries... but of course they can all be used for characters of your own devising as well.
If you go through characters real fast or see the need for a large supporting cast of NPCs, this book is likely to come in very useful.