Tupperware 15 piece FreezeSmart Container Set. No more guessing about when to use the food in your freezer. Tupperware FreezeSmart Containers have an innovative built-in "use by" date dial that lets you know exactly when food should be used for optimum flavor. These containers are perfect for freezing fresh raw foods such as meat, fish and poultry, fruits and blanched fresh vegetables. They're also great for storing these kinds of foods when purchased already frozen. Here are some of the features (see photos for additional features on pamphlet): - easy to set "use by" date dial; convenient fill line on container allows room for expansion as food freezes; dishwasher safe. To set "Use By" Date Dial: The 12 numbers on the dial represent the 12 months and the small dots in between the numbers represent the weeks within each month. The set includes the following: (1) tall round container = approx. 6" diameter; 7 1/2" tall (6) 9 3/4 oz containers (3) 2 3/4 cups containers (4) 4 oz containers (1) 2 1/4 cups container Not intended for microwave use Please note that I've had these items in storage but they have never been used.