Airtight seal with great elasticity power locks tightly with hollow-center silicon Microwave, freezer & top rack dishwasher safe Made from highest quality BPA free material for strong durability and safety Ideal for storage of flour, sugar, oat meal, coffee, tea LOCK & LOCK are the originators of the 100% air and liquid-tight food storage container concept, with the distinctive snap-down locking hinges and silicone seal which allows your food to stay fresh for longer. The four-hinged lids have each been tested to open and close more than 1 million times, to guarantee reliability, and the hollow silicone seal in the rim of the lid has superior compression and restoration properties to ensure an airtight seal. Lock Lock have manufactured these containers with their unique clip locking hinges for securing and opening the lid with ease. LOCK & LOCK Storage containers have a unique stacking design which can create up to 40% more space in your fridge freezer or cupboard. LOCK & LOCK containers have endless uses around the home, not just for food storage i.e. kid's toys, in the garage, DIY, sewing, first aid, organising drawers, etc, etc. These airtight containers are quite simply the best solution for food storage on the market. LOCK & LOCK stackable storage containers are microwave, dishwasher and freezer safe.