A premium device looks and functions like new and does not show any signs of usage. The battery health of this grading class is at least 85%.
An A-grade device can have minimal signs of usage which are not visible from 30 cm distance. It functions like a new one and its battery health is at least 85%.
A B-grade device has minor signs of usage but functions like new. The battery health of this grading class is also at least 85%.