The drill stop collar made of carbon steel, durable and reusable, will be firmly fixed in the place of placement, and is not easy to slip , does not damage the drill. Assorted Sizes3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm. Comes with 1 drill limit ring (8pcs in total) with 1pcs Allen key. Easy to UseDrill the depth stop with the set screw tightened, the collar will stay firmly in place. place exactly where you place them so the hole depth can be consistent, more convenient use of the round tenon! Drilling Depth ControlUse the drill hole depth 8 piece set of drill hole depth adjustable split ring screw stop collar to precisely control the depth of a hole you are drilling; Designed to hold your drill bit securely in place and grip the full diameter of your drill bit without the screw ever touching the arbor. Wide ApplicationsThe drill bit depth stop kit is used as a mechanical collar, which is very suitable for production and repeated drilling work, suitable for drilling wood or walls. Drill Stop Rings 3/4/5/6/8/10/ 12/16mm How To Use 1.Slide the correct size drill stop to the desired depth in the drill bit. 2.Align the locking screw with the floor (body). 3.Tighten the locking screw with the wrench provided. Drill Stop Rings 3/4/5/6 /8/10/12/16mm Size: 3mm 4mm 5mm 6mm 8mm 10mm 12mm 16mm Material: high carbon steel, aluminum alloy, stainless steel 304 Drilling depth stopper 8 pieces, drill bit depth stopper kit, depth stopper with hex key, mainly used to fix the drill bit, limit the depth of the drill hole, so that the hole depth can be consistent, more convenient use of tenon round. Package Includes: 8 x Drilling Stop Rings (3mm 4mm 5mm 6mm 8mm 10mm 12mm 16mm) 1 x 2.5mm Hex Wrench If the size of the drill bit is slightly different from the product size, please don't worry, it may be normally used. Drill Stop Rings 3/4/5/6/8/10/12/16mm Drill Stop Rings have an integrated screw to help adjust the size and the amount of pressure used to tighten the drill stop without damaging it. The Allen wrench will help adjust and install, uninstall the stop bits and can also be used for any other project. The drill stop kit fits most drill bits and easily adjusts to the exact depth required.