What does 'Grade A -' condition mean?

These items are those that couldn't quite be classed as pristine or renewed. Grade A- will be a good condition device with some light signs of use. Any wear to the device won't be visible during use or impede the functionality or enjoyment of the device. 

Please bear in mind that the grade of a device is purely cosmetic and will is not related to the functionality of the device. Every device, no matter the condition, is in full working order and has been fully checked and tested using industry-level software.