The Pentel Sharp is a classic mechanical pencil, produced essentially unchanged for 50 years, that packs a ton of functionality and a reasonable price. The lead advances reliably with a click of the cap. A metal clip holds the pen securely in your pocket or bag, and there's a replaceable eraser under the cap. And the Sharp is ergonomic and well-balanced. You won't regret having one or two of them in your desk drawer.