Features:Leakproof Cover: Our bamboo bottle caps are made of high-quality materials and are equipped with a removable silicone ring underneath, which can prevent your jars from warping and form an airtight seal, sturdy, durable and leak-proof, helping your jars stay fresh. Compatible Model: These tank storage lids are compatible with wide mouth mason jars. They can also use water cups and food storage tanks. How to Avoid Mold:1. Clean the lid after use. 2. Do not use water higher than 85 degrees. 3. When not in use, do not store any liquid in a glass bottle. 4. Not suitable for preservation or immersion in water. Specification:Material: bamboo Wide mouth: about 3.39x 3.39 x 0.79 inches Color: as picture shown Packing List:4*Bamboo Jar Lids (4 Wide Mouths ) Wide mouth: 3.39x 3.39 x 0.79 inches Sustainable bamboo top: Made from non-toxic, strong, and durable bamboo, our lids are not only eco-friendly but also beautiful. Perfectly sized straw hole: With a 14mm diameter, our straw hole is compatible with any straw smaller than 13mm, so you can enjoy your favorite beverages hassle-free. Leak-proof seal: Our lids come with a silicone sealing gasket that ensures a proper seal, so you never have to worry about leaks or spills. Set of 4: Each order includes 4 reusable bamboo caps with straw holes, so you can share them with friends and family or use them for different jars in your home.