Consistency is the whole product — a grade is only useful if it means the same thing on every order. We grade to a fixed rubric, photograph representative units, and re-inspect anything a buyer flags on arrival.
Cosmetic — assessed under controlled lighting: screen, frame and back are scored for micro-scratches, marks and dents. A+ is near-indistinguishable from new; C is fully functional with visible wear.
Battery — measured, not estimated. We report health so you know what you're reselling, and hold minimum thresholds by grade.
Functional — the 12-point test covers cellular, Wi-Fi, cameras, Face ID/Touch ID, speakers, buttons and charging. A unit fails the grade if any point fails, regardless of how it looks.