The phrase "magnetic flap" refers to a part of something, like a bag or a box, that uses a magnetic force to easily open and close.
Sentences with «magnetic flap»
Magnetic flap keeps the case securely closed and prevents damage to your device. (indabaa.com)
New magnetic flap puts keyboard at a comfortable angle. (pcmag.com)
The keyboard base folds nearly around the tablet with magnetic flaps while the padded exterior feels nice and subtle for carrying around the device. (techradar.com)