Our patent approved ibright is 16 LED lights built into a tray. It plugs straight into any iPhone, Android or USB (phone or tablet). No batteries necessary! ibright Smartphone Whitening System will have enough whitening gel for 4 applications (up to 9 applications). Simply use the 16 watt LED light for 30 minutes and repeat for 3-4 days or until desired results are achieved. Refills are available.