ITEM NAME:5V 2A Power Bank Charger Module Step Up Boost Dual USB LED PCB Circuit Board Gw.Output: dual output 5V 1A/2A. Input: 5V 1A. The battery lead do not touch the circuit board, so as to avoid short circuit. The circuit board B - for the battery negative, B + for the positive. Do not reverse, and then refused to burn the board, the battery is parallel welding.