They don't do shit and they last for as long as you want for them not to do shit for.
seriously, don't waste your money.
i think it works... my friend did that test thing on me before i even knew what it was and it worked. it has an insert magnet on it that aligns the iron in your blood
i think it works... my friend did that test thing on me before i even knew what it was and it worked. it has an insert magnet on it that aligns the iron in your blood