Does this exist in a source material that I can look into, or are you suggesting something homebrewed?
Are you suggesting that someone can fain a feat they do not have by using a magic item?
And are you tracking as to how other people were confused? Getting "Feat Rods" from "Feraotds" requires some IRL skill in Concentration, Decipher Script and Sense Motive on our parts. And that's only if we know to even try for a skill check.
I thought it was obvious. F E A T R O D S. Rods that contain feats.
And there are numerous examples of items that duplicate feats.... yet not one that I can think of are Reserve Feats.