The L030C is a black metal 70TW lid with pasteurization-grade plastisol liner and vacuum seal button. This lid is made of metal, which means it is fairly impervious to most processing methods. However, this metal lid has been fitted with a non-removable vinyl liner called plastisol, which has more restricted temperature and process requirements. When heated, and solidified, this plastisol liner creates an airtight, tamper-evident, hermetic seal. This cap has a pasteurization-grade (pasteur-grade) plastisol liner, which is recommended for both "Hot Fill and Pasteurize" and "Cold Fill and Pasteurize" heat process treatment. For "Hot Fill and Pasteurize" applications, minimum sealing temperature (temperature of the product in the jar after capping) is 149°F / 65°C, and the maximum process temperature tolerance is 195°F / 90°C. For "Cold Fill and Pasteurize" applications, minimum sealing temperature is 68°F / 20°C, and the maximum process temperature tolerance is 185°F / 85°C. Please test your product. Container & Packaging Supply is not responsible for compatibility of our products with your product and process. This cap has been equipped with a vacuum seal button. This button remains depressed when a successful vacuum seal has been achieved. For more information on the different types of plastisol liners and how to use them, please read our article, 3 Types of Plastisol Canning Caps and Why You Need To Know the Difference. This closure fits a container with a 70TW neck finish. This lid has a twist (TW) neck finish. That means that a container can be fitted with this TW cap (also called a lug cap) instead of a continuous thread cap. A lug cap usually requires about a 1/4 turn to close. A continuous thread cap usually requires a full turn.