Product useage:USB switching power supply meets the standard of switch power supply certification standard of GS/CE., has the function of overload protection ,over voltage protection ,constant voltage protection ,constant current protection capabilities .At the same time ,this product is mainly applied in LED lighting ,LED decorative lights areas , such as Christmas light ,copper light ,laser light, lawn lamp etc, and it also can be called in USB transformer, USB power supply, USB charger. According to different national safety certification, it can also be divided into GS, BS, SAA, UL and other USB power supplies.