Screw Pencil / Pencil

Screw Pencil is a pencil with the simple concept from screw and nut. When we use pencil frequently, the length of pencil is continuously decreasing and becomes hard to be hold. But, when a Screw Pencil is too short, we can just take another Screw Pencil with the different type of end and screw them together, then the length of pencil is enough to use again. Since every Screw Pencil can be used till the end, we can reduce the wasteness to the least. It not only means the less money expend, but the less use of natural resources.