Mast P40 Wireless Pen Machine with 2.5MM StrokeMast P40 Wireless Pen Machine with 2. 5MM Stroke Inspired by well known artists the entire body is round and smooth with a comfortable grip, more in line with the aesthetics of female artists. Specially tuned stroke and speed for artists,coloring efficiency are more efficient, reducing skin damage and making work easier. Equipped with 900mAh battery which can last 3~5 hours, worry free and smooth completion of your work. MAST is constantly striving to