Guangzhou Shuangdi Electronics Co.Ltd. professional manufacturepower bank for 10 years, high quality and compertitive price andgood services.our main products have build-in 18650 Li-on batterypower bank and poliyer battery ultry slim power bank and solarpower bank.our factory principle is Customer first, integritymanagement!welcome to your visit and ask. Sincerely lookforward to our cooperation