All-Natural Glass Vessels with Airtight Lids Ideal for Serving & Storing, Safe for Microwave Square Containers: 490ml Size: 4 7/8 " x 4 7/8" x 2 1/2" Snaplock - Clean & Fresh Not use for Oven Glasslock is made of tempered glass, guaranteeing excellent hardness & durability comparing with general glass and has an absolute airtight function keeping the liquid, moisture & smell inside. Specially there is no trace of harmful environmental hormone to human body in using microwave oven. These clear, stainproof glass containers feature a space saving design. Durable silicone seal provides airtight and leakproof storage. It is ideal for serving and storing, and safe for microwave cooking.