3 position vents in the lids, click to select the amount of steam venting required. a perfect range for all microwave heating, storing, cooking, transporting and eating needs. Made in New Zealand from 100 virgin polypropylene. Plates and steamers feature a removable insert to aid cooking and storing. All lids feature easy lifting flaps on all 4 corners for ease of use and safety. Dishwasher, freezer and microwave safe.