Calculation pen / electronic pen

Concept - Just use this pen. You can measuer the various value of some figure without
any instrument, cause you can see the exact value only using this pen by it's liqid crystal on. Benefit to user - Drawing it on the figure following its line, or make a figure on the paper you want to know of the value. This pen shows you the result of the calculation, the value of the figure on the liquid crystal on the pen about you want to know. And you can have the exact value from checking the
liquid crystal on this pen.This product will make you can save your effort, time, very effectively.