Refurbished Grade A: The best quality of refurbished device: near-mint condition, excellent cosmetic level, and little signs of previous use.
Refurbished Grade B: The second-best quality of refurbished device: light scuffing on the bezel and light scratches on the case or body as a result of gentle use.
Refurbished Grade C: The lowest-quality of refurbished device: 100% in working order but will have more scratches and signs of wear and tear as a result of daily use.
