This comfortable mechanical pencil makes it easy to advance the lead simply by shaking it. Plus, the tip is easy to see, and it features a sturdy tip pipe for a solid writing feel. It also has a switching function to lock the shake mechanism depending on the situation. When carrying it, you can turn the ring in the center to turn off the shake function, preventing the lead from accidentally coming out. When the shake function is off, the weight is fixed at the bottom of the barrel, providing a low center of gravity for stable writing. Size: 10.7mm diameter x 149.0mm total length Weight: 23.9g