1, Various sizes Drill depth stops of 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm and 16mm will fit drills of different sizes. 2, Carbon steel material Drill Bit Depth Stopper Made of high quality carbon steel, the surface is blackened, resistant to rust and corrosion, high hardness, not easy to wear and deform. 3, The depth stopper is mainly used to fix the ultimate drilling depth on the bit and precisely control the drilling depth. 4, Easy to Use Simply choose the appropriate size drill bit and stop collar, slide the collar over the bit and set the required depth using a ruler or d a depth gauge, then tighten the collar screw on the drill bit. 5, Warranty If you have any questions during the purchase process and u use, please feel free to email us and we will respond to you within 24 hours 8-bit depth stops, drill depth stop kit, depth stop with hex key. Features : Drill depth limiter, Allen key will help to adjust and install / uninstall the limiter. Drill stop ring, clamping device, drill depth control kit. Mainly used to fix the drill bit, limit the hole depth and make the hole depth consistent. More convenient to use a round wooden mortise. With the help of these products you drill holes of a precise depth quickly and easily. how to use: 1.Size of measurement 2. Choose the specifications 3. Loosen the screws 4. Tighten the screws Material: high carbon steel Dimensions: 3 mm 4 mm 5 mm 6 mm 8 mm 10 mm 12 mm 16 mm. The color black The package includes: 8 x depth stop, 1 x hex wrench product service: If you have any questions, please let us know and we will provide you with a satisfactory solution within 24 hours.