8 Sizes: 8 different depth stops, contains 8 different depth stop rings (3, 4, 5, 6, 8, 10, 12, 16 mm), which can be used for different types of drills, and a hex wrench. Durable: The carbon steel stop ring is made of high-quality carbon steel, durable and long service life. It will accurately control the depth of the hole you are drilling. Widely Used: The drill stop ring is suitable for repeated drilling operations, suitable for twist drills, wood drills, angle drills, etc. It can be used for drilling wood or drilling walls. High Quality Material: Carbon steel stop ring; the center of the pin is made of stainless steel. Wear-resistant and corrosion-resistant, it is a good tool for woodworking and wood crafts. Method: It is mainly used to fix the limit drilling depth on the drill bit and precisely control the depth of the hole to be drilled. It is not only suitable for standard drill bits, but also for curved head drill bits. The fixed screw collar will not damage the drill bit.