High Quality MaterialMade of high quality material with Japanese motor. Effective and durable. Fast & precise operationchuck speed 12,000rpm; Pen head diameter: 2.35mm. Even though small size possesses the big power, The cordless rotary tool has low torque and is only suitable for light grinding, engraving, etc. Electricpowered by 4 x AA type batteries (are not included in the package ). Easy to handle & strong. Widely UsedApplications include engraving tools, sporting goods, toys, phone chargers and delicate customization of jewelry, watches and glassware (Perfect gift for birthday, holiday, Christmas and other special occasions ) Specifications: Size: Length: 16*2cm Product weight: 102g Power supply: 4 x AA batteries (not included) Chuck Speed: 12,000RPM Material: Artificial diamond and plastic Package includes 1 * Engraver Pen