XINGLT MacBook Air Battery: [New Upgraded 3.0, Japan Electric Core, Cobalt Proportion: 99%]. Cobalt: 99%, The higher the proportion of cobalt, the better the performance of the battery. The manufacturing standards and testing standard are the same as those of the original battery supplier. New Upgrade 3.0 Quality: Battery for macbook air 13 inch with Japan High Performance Electric Core, 7200mAh Voltage:7.4V Capacity: 53.28Wh(Compatible with 7.6V/55Wh and 7.4V/53.28Wh) Package include: 1 x Macbook battery; 1 x keyboard protective film; 2 x screwdrivers; 4 x helper mat; 10 x replacement screws.