A storage box for whetstone, designed for Skerper professional which should be the same as the Knifewear stones and the Naniwa standard. These are an improvement and upgrade from the karton box they came in. 

The stone will sit in the box while sharpening, there is a bottom part that should be printed in TPU to give it some grip while you sharpen. The TPU part can just be pushed in place, no glue needed. The top part has a groove that will fit the TPU part. This makes the boxes stackable.