I experiment a bit with the rod, moving it around and pressing the button to see what happens.
also, I make a check to see what's binding me to the rod:
Craft(alchemy):(1d20+13)(If it's the effect of some substance)
Spellcraft:(1d20+11)(If it's the effect of a spell)
Knowledge(Arcana):(1d20+11)(If it's part of the item's effect*)
*does not actually identify the item; only identify scrolls or bardic knowledge can do that beyond doubt