Milton Treat Airtight Containers, Clear, 1000 ml 2 piece set; Easy lid locking system; 100% leak proof The Milton Air Tight Containers are made from Polycarbonate which makes them absolutely unbreakable Their Unique Air Tight System Which Provides An Air Tight Sealing Ensures That Your Eatables Stay Fresh And Crisp They Are 100% Leak-proof, Unbreakable and stackable Microwave safe without the lid and dishwasher safe