The plastic jar cap with a silicone sealing ring is suitable for 70mm regular mouth Mason jars.SpecificationJar Cap:Color: Silver ToneMaterial: Stainless SteelInner Diameter: 70mm/2.8"Size: 74mm x 17mm/2.9" x 0.7" (Dia.*H)Sealing Ring:Color: TranslucentMaterial: SiliconeThickness: 3mm/0.1"Inner Diameter: 55mm/2.2"Packing List: 1 Set - 3 x Jar Caps and 3 x Sealing RingsAdvantage1. The can cap is made of durable stainless steel material with a silicone sealing ring, which is sturdy, waterproof, rust-proof and not easily deformed.2. The edge of the Mason jar lid is designed with non-slip ribbing for easy opening and tightening of the jar cap.3. The jar lid has a good tightness to keep your contents fresh, and it is great for the wide-mouth jar to dry storing or freeze in the refrigerator.InstructionEasy to use - just install the caps on the jar mouth and tighten it to seal.NOTE: Make sure the right size you need before ordering. Manual measurement allows 1mm-2mm of error.