This replacement battery has an integrated microchip to prevent overcharging and lengthens battery life. Best replacement battery with long-time standby and talk time. Light weight, high capacity and low impedance. For iPhone 6s Plus (5.5") ONLY High Quality, 3 Year Wanrranty, Grade A+ battery,Brand new 0 Cycle. ISO9001/FCC/CE/MSDS/UL /un38.3 Certificated.     Capacity: 2750mAh Voltage: 3.82V Working Temperature: -10~40? Limited Charge Voltage:4.35V Life Span: After 300 times cycle capacity retention= 80% Type: Internal Li-ion Polymer Battery Chemistry: Li-ion Weight: about 50g Size:121.5*49.6*3.6mm 1.Due to limitations on space, the instruction only provides some key steps,it is unable to describe vividly how to replace the battery.