Durable silicone: silicone without bisphenol A and suitable for food use to offer a resistance of trust and optimal versatile performance: it comes in 6 different sizes and stretches up to half of its size to adapt to round containers of different sizes hermetic and Transparent: They create a hermetic closure: they contribute to conserve drinks and meals already made as leftovers and much more fresh and stored in an orderly manner: transparent design that allows to easily search and organize what has been stored