Features HIGH PRECISION BRASS CLAMP HEAD Our mini electric engraving pen is equipped with a brass clamping head for high concentricity and stable clamping. 2.35 Shank Diameter Grinding Drill: The mini electric engraver is stable and can be used for 2.35 shank diameter grinding drills. Suitable Materials The electric engraving grinding pen can be suitable for glass, metal, wood, plastic, leather, jewelry, etc. Comfortable handle: the electric engraving grinder is easy to use at the actual work and sits comfortably in the hand thanks to its 10W power. Wide range of applications: the electric grinding pen has a 380mAh battery and is suitable for engraving sporting goods, toys, chargers, as well as delicate jewellery and watches. Specification: Item Type:Mini Electric Engraving Pen Material: stainless steel, brass. Clamp: 2.35 Depth of clamping head: approx. 25 mm / 1 inch. 3 speed speeds: 10,000, 15,000, 20,000 RPM Power: 10W Battery capacity: 3.7V lithium battery x 1, 380mAh (comes with built-in battery) Charging input voltage: 5V 2A Package list: 1 x engraving pen. 1 x charging cable. 2 x engraving needles. 1 x user manual (English language not guaranteed) Package List 1 x Engraving Pen 1 x Charging Cord 2 x Engraving Needle 1 x Instruction Manual