REGULAR MOUTH SIZE: Fits standard "regular mouth" mason jar lids (75mm lids) For MASON JAR FIT: Compatible with Ball and Kerr and other mason jars while using unlined plastic mason jar lids SAFE: Food grade silicone, dishwasher safe, freezer safe, heat tolerant, reusable MULTI-USE: Great for everyday storage, and travel, storage of dehydrated food and much more Keep in liquids, keep out bugs and moisture. All the things you need for an airtight seal are provided by these silicone rings.if you have one piece metal lids, these will provide a sturdy liner. If you currently have lids with foam liners, throw the foam liners away and enjoy our easy clean silicone liners. Now you can take your "meal in a jar" to the office without worrying about leaks. You can store that beef jerky [with a moisture absorber] without worrying about added humidity. You can store that flax meal in the fridge ... without picking up those strange fridge smells. Even confidently use your mason jars to shake up homemade salad dressing! Product Testing: We have tested these jars with both of the following and had no leakage: unlined plastic mason jar lids and one piece metal lids. We put colored water in these and tested upside down and tipped for several hours and had zero leakage. It was easy to slip the liners in the lids, they not fall out, and they were easy to screw on the jars. Colour:White Material:Silicone Size:70mm Package Contents: 48* Silicone Sealing Rings Gasket Only the above package content, other products are not included. Note: Light 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.