Item description:

In one Portal 2 save you can have 8 custom saves and 2 autosaves. Ignore all autosaves. Most trophies will pop on load when you load its save, at most you will have to press 1 button (One trophy requires you to pick up a turret on a moving belt). One load gives one trophy, after you have achieved it just go back to the main menu for the next one.

Going to the hub in Co-Op will give you 9 trophies, this work on all four saves.