These inserts are made to fit in a IRIS 4x6 photo box. The top insert can be easily taken off to access accessories stored bellow 

The top tray can hold 5 pens or pencils and the Accesory tray can store 13 pentel lead cases, 1 eraser refill tubes and one pentel click eraser . However if you just want to store extra things the bottom tray with no dividers is just a tray that still works

Personally, I use it to store my pencils as the box is pretty thin and can fit in my backpack but still protect my pencils. I also used adhesive foam at the top of the case to reduce rattle and protect them more but it isn't required i just had some laying around. and the pencils look cool on the clear case.