DA86 2UUL Mini Grinder Pen Set With 10 Grinding Heads For Mobile Phone Motherboard PCB Chip CPU Component Repair Grinding Tool. Design: It is a mini-sized, lightweight (58g) polishing pen designed for comfortable, one-handed use in confined spaces. Performance: It features a high-speed motor reaching up to 15,000 RPM and torque compensation technology to maintain stable power during use. Features: The grinder offers 5 adjustable speed gears with an LED display and a smart memory function that recalls the last-used setting. Power: It is powered by a built-in 320mAh rechargeable battery and charges via a 5V/1A input. Accessories: The set typically includes various grinding heads for different applications like polishing, drilling, and cleaning components.