The MacBookAir 11 "1465 has built on the back of special Pentalobe screw of Apple with this screwdriver should be able to open the Macbook without damaging the screws but the supplied tool did not fit on the screw The screwdriver is too small result:.... The difficult to be obtained, 15 Eur expensive screws are screwed up, so that the technician can see the Apple store that the device has already been opened. Result: warranty valid The state of the screws according to Apple employees the only feature to detect whether a device already! has been opened. Conclusion: Using the screwdriver, the device can open and screw it again, who, however, is still under warranty and still want to open the device (not to be sent to Apple, for example, about its data), should refer to the desired Pentalobe key where He / she also gets one that fits and leaves no marks. Delivered I was a Torx key. Very annoying!