Grade A devices:
Grade A devices are like new. However, the devices are used and may show slight signs of use on the screen, back cover, or chassis. Devices that show no signs of use are classified as "new."

Class B devices:
Class B devices are in excellent condition. However, they have been used and may therefore show very slight signs of use on the screen, back cover or chassis.

Class C devices:
Grade C devices are in very good condition. They show minor signs of use on the screen, back cover, or chassis.

Grade D devices:
D-grade devices are in good condition. However, they have more significant scratches on the digitizer, back cover, or chassis. D-grade devices power on with a good LCD screen.