★ [Various Sizes]: 12 stop rings with an inner diameter of 3/4/5/6/7/8/9/9.5/10/12/14/16mm, including 2 hex wrenches. ★ [Various Sizes]: 12 stop rings with an inner diameter of 3/4/5/6/7/8/9/9.5/10/12/14/16mm, including 2 hex wrenches. ★ [Various Sizes]: 12 stop rings with an inner diameter of 3/4/5/6/7/8/9/9.5/10/12/14/16mm, including 2 hex wrenches. ★ [High Quality]: Made of stainless steel, durable, suitable for high carbon steel drill bits, can be fixed in any position along the drill bit. ★ [Limit Drilling]: Used to limit drilling to prevent drilling too deep, such as drill bit limit ring, clamping device and positioner. ★ [Precise Adjustment]: The stop ring can be adjusted quickly and easily at any position on the cutting flute/shaft. By preventing the drill bit from being too large and drilling, accurate drilling results can be obtained. ★ [Won’t Damage the Drill Bit]: The screw type collar will not damage the drill bit, which can prevent errors and waste of materials, so it is worthwhile., Manufacturer: Entatial