The ThinkPad Pro Pen with 2,048 levels of pressure sensitivity is an ideal input solution to give the user a precise content-creation experience. Users will also enjoy easy access to right and left click buttons built into the shaft of the pen that provide additional tools for data interaction. This pen can be stored in the system's pen slot. With an internal rechargeable battery, the user can easily charge it in the pen slot for a battery life of almost 19 hours from one charge.Diameter: 6.5 mm Pressure sensitive: 2,048 levels Battery: rechargeable battery in side for fast charging Could be stored and charged in ThinkPad system