The “Blossom uCap Silicone Storage Cap – standard clear” is a storage cap for standard-mouth Mason jars, which provides a tight seal for convenient storage. The one-piece / multi-use storage cap locks in freshness with a double air-tight seal, and will never ever rust. It snaps on snuggly over the mouth of any standard-mouth Mason jar. This product is made from food grade clear colored silicone, and is fully compliant with FDA food-safe silicone requirements. Another innovative, lifestyle enhancing, fun idea from Spice Ratchet.