️[Chuck Accepted Drill Range]: 3/8 inch (1.5 mm to 10 mm.)） ️[Premium Material]: This hand drill bit set is made of high-quality steel, which is sturdy, portable and durable to use, providing a long service life. Thick handle made of high-strength ABS plastic for maximum comfort. The hollow handle can store the spare drill chuck. ️[Easy to Install]: Installing the chuck and bits involves only twisting and screwing actions. A cleverly designed chuck key is provided to help you elegantly rotate the upper part of the chuck to change bits. ️[Special Design] The double-pinion design ensures smooth and flexible operation without jamming. 2 gears make the work more robust and efficient. ️[Wide Application]: Suitable for wood, bamboo, soft and thin iron, copper, aluminum, plastic, PVC, acrylic, fiberglass board, circuit board, etc. Note: This hand drill is not suitable for drilling hard metal materials, tiles, masonry, concrete.