Zaib is a trusted brand on e commerce platform (use in microwave without Lid only re-heating purpose) interior is made of Stainless Steel and Exterior is made of Polypropylene; Premium Quality Stainless Steel Multipurpose Microwave Safe Serving Mixing Storage Snack Bowl with Air Tight Lids MICROWAVE SAFE STEEL BOWL: India’s first stainless steel utensil microwave safe euro bowl designed for a complete lifestyle; easy to clean, unbreakable bowls & contains three different sizes; airtight plastic lid keeps contents fresh for long time & made of stainless steel SPECIAL QUALITY: Deeper prep bowls than standard bowl sets which helps to reduce splatter and have flat base that stays firmly stable to your countertop. Heavy gauge food grade steel makes these mixing bowls dent & rust resistant and never retains odours, bacteria, or stains