Cobalt bracer
 

I know the bracer is war only but can the effect be activated from inventory? Can anyone use it to shrink?

Has to be equipped.

I don't think there are many alternative to shrink pots, until luclin and the wand...

It has to be equipped to use, it can only be used indoors, and only warriors can equip it, but it can be cast on group members.

Just like the rest of Cobalt clicky gear, must be equipped in order to use.