FCENDS Silicone Replacement Seal Rings for Jar Lids, 12 Pack, 2.9 Inch Inner Diameter

These are the gaskets alone — the flat silicone rings that sit in the underside of a jar lid and go hard or split long before the jar does.

Dimensions decide whether they fit: 2.9 inches inside, 3.7 outside, 0.09 thick.

The listing describes the fit two ways. One bullet says they suit wide-mouth mason lids of 3 inches; another says regular-mouth canning jars. Measure the lid you have.

Silicone is elastic enough to stretch a little over a slightly different diameter, which is why the maker claims one size covers jars from half a litre to two litres.

White, odourless and washable, so they can go back in after a rinse rather than being thrown away with the old ring.

Twelve to a pack, which covers a shelf of jars in one go. Beyond food, the maker mentions sealing jars of soap, paint or craft materials.

• 12 silicone rings
• 2.9 in inside, 3.7 in outside, 0.09 in thick
• White
• Fit described as wide-mouth in one bullet, regular-mouth in another
• Reusable and washable
• Quoted to suit 0.5 to 2 litre jars