AIR AND WATERTIGHT - Four side locking system and hollow-centre silicone seal for superior airtight lockage - This airtight container can reopened and closed more than 3 million times FREEZER AND MICROWAVE SAFE - Plan and freeze your meals or leftovers for later - Use this plastic container in the microwave to reheat your delicious lunch or dinner in a few minutes DISHWASHER SAFE - For complete convenience, this batch cooking containers is completely dishwasher safe, meaning you will save time cleaning up every day SPACE EFFICIENCY - This food containers with lids is designed to stack different sized containers on top of one another, allowing up to 40% more storage space in the fridge or cupboards BPA FREE - Your safety is our priority - These meal prep containers with lids are BPA free and friendly to the body using superior durable and heat resistant raw materials