We choose manufacturers who invest a large amount of capital in the R&D and quality enhancement, which ensures the best quality and performance of apple A1079 battery. Most of our A1079 apple battery are tested manually again after tested by electronic devices,so the defect rate is very low. As for the raw materials, we never sacrifice quality for lower price; we always choose the highest quality A1079 battery when take advantage of lower costs. We value quality as the life of our company: save your huge opportunity costs of using other products, save your delivery costs of returning the defects, save your transaction fee of refunds.