Keep your foods freshly preserved with Ball Regular Mouth Mason Jar Lids. Compatible with all Ball Regular Mouth glass Mason jars, these canning jar lids offer the sealing quality that canners have trusted for generations, ensuring no oxygen gets into the canning jar so your food remains preserved just the way you created it. Whether you're preserving jam to enjoy for long periods of time or storing freshly made salad dressing for the coming week, Ball Mason jar lids seal in freshness to keep your food tasting great. When canning, lids are for one-time use only.