This grinder is compact and convenient to operate, with pneumatic design. It does not need electricity, saves time and labor, and is suitable for various operations such as polishing, grinding and engraving. Features: Made of fine quality material, wear-resistant for long using time. Effortless pressing plate switch, convenient and comfortable to press. With 3mm and 6mm chucks, the application scope is wider. The grinding bit is easy to assemble and disassemble. Compact size, easy to carry and long time operation is not tiring. Specifications: Type: Set A, Set B (optional) Length of grinder :155mm / 6.1in Air inlet : 1/4" Chuck: 3mm+6mm Package size: Set A: 185 * 70 * 47mm / 7.3 * 2.8 * 1.9in Set B: 220 * 190 * 50mm / 8.7 * 7.5 * 2.0in Package weight: Set A: 480g / 1.1lb Set B: 800g / 1.8lb Packing List: Set A: 1 * Grinder 2 * Wrench 2 * Chuck 1 * Connector Set B: 1 * Grinder 2 * Wrench 2 * Chuck 10 * Grinding Bits 1 * Connector