[Size] - These lids and straps are suitable for wide mouth mason jars. The outer diameter is 3.35 inches (86 mm). [No need to reuse] - The canned lid is designed for one-time use. Repeated use may cause your jar to not seal properly. These lids have a special sealing compound around the edges and are only suitable for one-time use. But the strap can be reused. [Widely used]-If you keep food at home-you are likely to use Mason type jars. At this time, you need to choose the appropriate can (normal mouth jar or wide mouth jar), in addition, when you choose the mason jar lid, please make sure its correct size colour:Gold Material:Tinplate Package Contents: 20 x canning lids 20 x bands Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.