Tupperware Vent N Serve Small Round Set Black These round versions of our popular microwave-ready containers feature a vented silicone valve that's virtually liquid-tight This easy to open & close silicone valve also lets steam escape more rapidly when reheating and can be easily detached for cleaning Take foods directly from the freezer or refrigerator right to the microwave for fast and easy reheating  perfect for leftovers or meals on-the-go Includes 1 3/4, 2 1/2 and 3 1/2-cup/400 mL, 600 mL and 800 mL round containers Tupperware Lifetime Warranty