WATER & AIRTIGHT - All 4 sides of these food container with lids lock for an airtight seal. This means to spills whether that be in your fridge, freezer or if you need your meal prep on the go RECYCLABLE BOROSILICATE GLASS - These food containers are made from tough borosilicate glass that is even more shatterproof than tempered glass. This is to ensure this glass ovenware really does last a lifetime RECYCLED LIDS - Eco Ovenglass products are all topped with LocknLock's iconic Eco lids made from left over production plastic to ensure nothing is wasted. Lid colours may vary as no two pieces are the same DISHWASHER SAFE - As well as being dishwasher safe, LocknLock Eco ovenglass products are microwave & freezer safe too. An all-round sustainable and stylish product that is practical to match. They're also BPA Free OVEN SAFE EXTREME RESILIENCE - Turn up the heat with these glass food storage containers. Eco Ovenglass is resistant to extremely high oven temperatures, withstanding anything up to 400°C (glass dish only) so you can cook and store your culinary creations in the same dish