Tested under strict quality control standards. CE and ROHS certified.</br>Grade A cells ensure longer battery life (500+ cycles) and high-speed?? efficient charging.</br>Built-in IC chip prevents overcharging. Full NFC functionality. Guaranteed to fit your phone.</br>Voltage: 3.85V. Capacity: 6440mAh.</br>Package contents: 1 x cell phone backup battery?? 1 x back cover?? 1 x user's manual</br></br>Product Description</br></br><b>Upgrade via replacement.</b><br>We wouldn't give you anything less than the best. Grade A cells chosen from among the top 10%. Rigorous inspection tests to ensure reliability. A built-in IC chip to prevent against short-circuiting. Complete NFC functionality. What does this all mean? In terms of quality?? you won't find a better