Features High Concentricity Brass Clamp Head: Ensures steady clamping with high accuracy, compatible with 2.35 shank diameter grinding bit. Versatile Applicability: Suitable for engraving glass, metal, wood, plastic, leather, jewelry, nail art, and various daily crafts. Comfortable Grip Design: Ergonomic hand grip for comfortable usage, powered by a 25W motor, providing precise control. Wide Battery Application: Equipped with a 280mAh battery, suitable for engraving sporting goods, toys, chargers, delicate jewelry, and watches. Integrally Firm Grinding Bit: Provides integrally firm support for various engraving tasks, ensuring stability and durability. Specification: Item Type: Electric Engraving Pen Material: Stainless Steel And Brass Rotational Speed: 5000-25000r/Min Maximum Power: 25W Power Supply: USB Charging Voltage: 3.7V Battery Capacity: 3.7V Lithium Battery x 1 (280mAh) (Shipped With Built In Battery) Package List: 1 x Engraving Pen 1 x Charging Cable 3 x Drill Bit 3 x Small Saw Blade 32 x Carving Needle 1 x Wrench 1 x Instruction Manual 1 x Set Screw 1 x Storage Box Note: Use the incisive tip of the pen with care. Package List 1 x Engraving Pen 1 x Charging Cable 3 x Drill Bit 3 x Small Saw Blade 32 x Carving Needle 1 x Wrench 1 x Instruction Manual 1 x Set Screw 1 x Storage Box