Ball 37010 wide mouth canning jar reusable plastic storage caps, BOX OF 8. White color. Ball Wide Mouth Plastic Storage Caps are ideal for storing or freezing with Wide Mouth Glass Preserving Jars. The versatile Ball Wide Mouth Plastic Storage Caps provide more ways to store your creations. You may refrigerate, freeze or store. Each package contains 8 reusable plastic storage caps. Not for use with the FreshPreserving process. Dishwasher safe. Does not contain bisphenol A (BPA).