Unlike other earbuds that are made of plastic, the MIFO O5 Gen 2‘s case features an all-metal design. In terms of durability, the frosted metal case is way better than the traditional plastic ...

In panel d, the contour lines from 0 to 2 fm/Å3 by the step of 0.2 fm/Å3. Arrows in panel c denote the directions of oxide-ion O1-to-O5 migration.