The uni-ball KuruToga Twist and Turn 0.5mm Mechanical Pencil Starter Set (1751934) is the most advanced mechanical pencil ever. The KuruToga (Japanese for Twist and Turn) has an exclusive and patented rotating mechanism that resists lead breakage. As you write, the engine rotates the lead to maintain a sharp point and avoid flat spots on the lead. The Starter Set includes uni-ball Diamond Infused Leads for added strength and smooth writing performance. It is available in 0.5 mm perfect for intricate tasks.