Synonyms: Hidden Object
Well Prepared is a Prowess, this special kind of Feat can't be acquired until the third level. A Prowess is a special action that can only be done once per scenario. Unlike normal Feats, it can be acquired several times.
Thanks to constant paranoia and careful preparations, you happen to have the exact item you need right now !
It could be anything that you can carry and afford.
A rope, a bow with arrows, a chain mail, a bar to block a door, a bottle of alcohol. Anything at all.
The only limitation is that it should be something easy to get, for example this cannot be an antidote, a smoke bomb or a powerful poison.