I was a little hesitant to buy these until I saw them in a video with Adam Savage and he had them in his shop. I bought this set and they are extremely well made, very heavy duty. You don't have to fill the trays up with drill bits, they work great for sorting small parts also. One way to improve them would be to make a better way for them to stack. Metal on metal lets them slide around too much. I attached some rubber feet and those gave them enough grip to not slide around when stacked. Really love these for all my small components!