Good and quick service. Replacement battery doesn't seem to have the capacity advertised (4570 vs 5100 mAh) but it has fixed the issue of the laptop unexpectedly turning itself off whenever put under heavier load when battery charge was below about 40%.
About the product:
Two issues: (1) After calibration the system shows a full charge capacity of 4570 mAh, lower than the claimed 5100 mAh when I bought the battery. (2) You recommended (and I included in my order) the set of tools to complete the battery installation. However, the set of screwdrivers supplied didn't include the P5 screwdriver necessary to open the back of a Macbook Air, so I had to buy a P5 screwdriver from another source. Not sure if that was a mistake in what was included or not. Either way the specs on the toolkit should have been detailed enough for me to see if it included the screwdrivers I needed to complete the installation and or the tools supplied/recommended should have been adequate to complete the job.