1、SPEED RANGE: Electric engraving pen with an input voltage of 5V and a speed range of 6000-15000r/min, suitable for a wide range of applications. 2、CLAMPING RANGE: The clamping range of this engraving pen is 0.5-3.2mm, can be installed with suitable drill bits or grinding heads, stable and reliable. 3、BUILT IN BATTERY: This rechargeable engraving pen has a 1500mA lithium battery, and equipped with a charging cable to ensure long term operation. 4、PORTABLE DESIGN: The polishing pen is portable design, which is comfortable to hold, labor saving to operate, and greatly improves work efficiency. 5、APPLICABLE MATERIAL: Can be used for materials such as glass, metal, wood, plastic and leather, etc., suitable for lettering, carving, nail polishing, etc. 6、METAL STRUCTURE: This carving pen is made of excellent stainless steel and brass, wear resistance and impact resistance, have a long service life.