The BOSCH 7 pc. SpinLOCK Universal Hole Saw Kit is designed for users who are looking for convenient way to get clean fast cuts in such materials as wood, metal and plastic. The universal arbor fits all brands and sizes to simplify diameter changes, facilitates faster plug removal and enables tool-free accessory install. It's made to let you change hole saws in seconds. The pilot bit is designed for a variety of materials as well. The hole saws feature the Progressor tooth design, which features alternating teeth size for performance, cutting faster and lasting longer in wood, metal and plastic materials. The 2-in-1 cuts are clean and fast. Large teeth are optimized for fast cuts in thick materials; small teeth are optimized for clean cuts in thin material. The hole saws are made with 8% cobalt alloy and are designed with reinforced shoulders.