Use this red silicone lid with canning jars to create eco-friendly "to-go" mugs that are perfect for your favorite homemade drinks. Providing a leakproof seal, the stay-cool silicone lid helps keep beverages warm or cold. Suitable for use with any standard small-mouth canning jar. Silicone will not absorb flavors or odors. Each lid has a hole for a straw (sold separately). 2 1/2" diam. A Williams-Sonoma exclusive.