ClearView® crystal clear OPS lids with built-in anti-fog are the perfect complement to our MealMaster™ microwaveable bases. Great for home meal replacement, entrees or sides-to-go, these containers are perfect for the grocery store hot or cold display case. Featuring a ZipSeal™ closure for increased leak resistance these containers transport well from store to door. Medium Flat Lid. Food Container Type: Lid; Material(s): Polystyrene; Material Type: Plastic; Color(s): Clear.