This Charles Viancin Set of 2 4" Extra Small White & Blue Snowflake Lids is made from BPA-free, food grade silicone which seals tightly on all smooth rims to create a watertight and airtight seal. Safe for use in the oven and the microwave, the lids eliminate the need for wasteful aluminum foil and plastic wrap. The lids are also dishwasher safe for easy cleanup. Made in China. Each lid measures 4" in diameter.