Great & reliable product, started working fine as soon as I installed it a month ago & still doing very well, charging quickly & holding charge as expected. It is giving me over one hr of charge w/o the charger. However, installation on this particular MacBook is not trivial & takes patience & care, as it is a very delicate operation; I had to remove a total of 31 screws, 6 of which were from the case attachments, but rest of screws had to be removed from motherboard & installed back after the new battery was installed. Removing the battery which is attached to the case via a strong glue was tricky, but with Patience & a good thin scraper with round corner will do the job fine. I highly recommend watching YouTube videos on this MacBook Pro model to make sure you do it right. It is a very delicate operation & keep track of which screw goes where, since there are many types & sizes, I recommend making a drawing of inside of your MacBook Pro & using a clear scotch tape to tape the screws on image of every component you extract the screw from to make sure you don't lose track & they don't get lost. You'll feel very proud when you finish installation & all works fine, you don't need any special skill, just patience & paying close attention, Good Luck!