Store, heat and freeze meals, produce and ingredients with Bentgo's Signature food storage system. Oven-safe glass containers give you a clear view of contents, while the silicone-sealed tempered glass lids are airtight and leakproof. The lid's built-in steam valve allows proper venting and splatter-free heating for warming up foods in the microwave. The 18-piece set comprises round, square and rectangular lidded containers in a variety of sizes.