MasterClass All-in-One containers are very handy for all kinds of cooking, storing, heating and refreezing. But after all that heavy use, lids may be starting to lack their former glory, even though the stainless steel dish keeps in perfect shape. These interchangeable lids will fit the 500ml, 750ml and 1000ml containers. The lids are airtight, leakproof and complete with a pop-off steam vent for fuss-free microwaving (up to 1000 kw)., just like the ones you used before. Larger lids are also available for larger containers.