The 68W15L is a 15mm polystyrene white foam ated (PS-22) liner insert with a pressure sensitive ating. Pressure sensitive liners create an actual seal, providing an extra level of protection mpared to a basic foam liner. They are best for dry products and can at times, work with thick liquids such as crea and sauces. Generally, these liners are not rOkaymmended for liquids and oils