The Lock And Lock Ezlock containers are scientifically designed for stacking both upward and sideways to save space on the shelf. Lock And Lock multi-purpose and multi-functional containers meet consumer’s different needs. Absolutely keeps your food with fresh with double locking system. Hollow center silicon seal between the lid and the container enables superior airtight lockage compared to rubber or full silicon. 4-side of locking system makes it possible to be airtight due to equal pressure to all 4 sides.