High quality PP plastic,Non-toxic,moisture proof, dustproof,sturdy and durable. 

The items stored in the box can be clearly seen for easy finishing. 

Inside dimension 3.54" x 2.36" x 0.86",Can be used as a standard size card case. 

Can also be great for organizing small items,small parts,crafts, beads, coins, jewelry and others. 

You can number each box, which will greatly improve the efficiency of your work and study.