What grade is this case? (B6)

1401206-4b-347-10x-1024x1024 1401206-4b-347-10x2-1024x1024 1401206-4b-347-20x-1024x1024 1401206-4b-347-20x2-1024x1024 1401206-4b-347-20x3-1024x1024 1401206-4b-347-20x4-1024x1024