Full disclosure - 3M gave me a free sample of this product to evaluate.
This is a 3 ft x 2 ft sheet of dry erase material. It came with a dry erase cleaning cloth. It does not come with dry erase markers. The full back of the material is sticky  - not just the corners. It can stick to a wall or other flat surface - perfect for over an old chalk or bulletin board. It is thin enough to cut to fit just about any area. It comes in a roll and I was concerned it would want to keep rolling up while trying to adhere it to a flat surface - it did not - it flattened easily. I'll be using part of it for the inside of a kitchen cupboard to write notes; the rest of the sheet will be mounted on an old bulletin board. You can also get this product in 4 ft x 6 ft.