I bought a secondhand 29W charger, and I'm trying to tell if it's genuine or counterfeit. I've heard one way to tell (without ripping it apart) is to weigh it, but I couldn't find anywhere on the web how much this thing should weigh exactly. On Amazon it's saying it should weigh 130g, but I'm not sure if that's on the charger only or including the box & papers and all that. Mine is at 91g (without duckhead), 122g (with 220V Euro/Asia 2-pin plug). Can anyone with a genuine charger from Apple verify these numbers (especially without the duckhead)? Thanks.