This sort-roller consists of two parts; the body of the snail (wheeled base) and its shell (cylinder shape). Once you pull the snail body, you can watch its shell magically roll round. The shell can be taken off. It contains six block shapes that can be taken out and removed from the shell. The shell has six different shaped holes which works great as a puzzle for small children because they have to sort the shapes and push them through specific holes. This helps any child to distinguish the difference between shapes and it enhances their dexterity.