1. SIMPLE DRILLING IN VARIOUS SIZES: With 8 different sizes of precision drill stop rings, you can easily complete any drilling project. The rings allow you to quickly and accurately adjust the depth. Package includes: 8 PCSx drill depth stop rings 1 x hex key. 2. QUALITY STANDARD: These depth stop rings are forged from quality carbon steel and finely crafted to ensure they won't break even with frequent use. They are suitable for your drilling needs. 3. PROCESSING: Use a hex key to tighten the adjustment screw on the selfcentering drill guide stop ring for depth control. Say goodbye to uneven drilling depths and effortlessly repeat drilling tasks at the same height. 4. IMPROVED DRILLING CONTROL: Precise depth measurement with our selfcentering drill guide stop ring set makes accurate drilling easier. Prevents burning the material surface, minimizes errors and waste, and enables efficient drilling.