This cube is badly designed - the shapes are too similar so it is very difficult for my 20 month old to find the right slot. In addition, other shape sorters use color coding on the cube to help find the right slot, this one doesn't. The lid won't stay on, it slides off when the box is turned over. As it has to slide on my toddler (who adores putting lids on and off boxes) can't put it on himself and gets very frustrated. It is made of wood, but it is cheap MDF and poorly constructed. There are much better shape sorters on the market.