Feature 1SCREW LOCKING: The drill stop ring is locked with screw, the clamping torsion is up to 4.5kg to prevent the plate from being punctured. 2OPEN DESIGN: These drilling depth limit rings are open type design, which can be fine tuned to meet more clamping requirements. 3EXCELLENT METAL: These stop rings are made of excellent zinc alloy, corrosion resistant and wear resistant, and has a long service life. 4MAIN PURPOSE: These stop rings are suitable for carbon steel bits, which are clamped to limit the drilling depth, convenient and practical. 5SPECIFICATIONS: Including 3pcs metal stop rings, 3 sizes of 6mm, 8mm and 10mm, and equipped with a hex wrench, easy to operate.SpecificationItem Type: Drill Bit Stop RingMaterial: Zinc AlloyColor: SilverUse: Applicable to carbon steel drill bits, which can be safely locked at any position along the drill bit .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List3 x StopRings1 x Hex Wrench