Each of the mobile devices in your life has its own, specific charging profile that dictates how much, and how quickly, it can charge. Most chargers are designed with a one-size-fits-all approach; they don't support the requirements of individual devices. Griffin ChargeSensorTM technology senses the charging requirements of any device plugged into it, and adapts itself to that device. The result is a single, truly universal AC charger that provides optimum charging for all your USB-chargeable devices. This product is Guaranteed for Life. If it fails to perform as specified, we'll repair or replace it. See www.griffintechnology.com/warranty for our full warranty policy.Griffin