It works 100% flawlessly on OS Monterey! Great Battery Life: Battery is guaranteed to have 70% health or better upon arrival.For the most part, their warranties only cover parts installed by their company. That means, if the logic board, the most expensive part of your computer goes bad - you're not covered and you're stuck with a paperweight. Furthermore, newer MacBook Pros like this one have very few removable parts, as most of the expensive components including the SSD & RAM are soldered to the logic board. This is the best way of ensuring full coverage on your Machine with absolutely no surprises. Check out what our current customers have to say about us by checking out our feedback!