KIT BOX is a storage box with a height of 2.0 inches (50 mm) (5 cm). Overlapping a lot of materials or works can cause extra load on the underneath or damage when retrieved. Designed to be low in height to protect the materials and avoid strain. Made using AF hardboard that is weak alkaline paperboard (made by Tokai Paper Co., Ltd). AF hardboard is a cardstock with a fold strength, surface strength, and is an excellent material for preserving materials that have passed PAT (Photo Activity Test) No glue or fasteners required so anyone can assemble it easily. When assembling, fold all the folds at the first and then assemble them to create a beautiful finish.