This set includes ten trays made of thick plastic moulded to form the most common types of land and water forms: lake, island, gulf, peninsula, strait, isthmus, bay, cape, archipelago and system of lakes. The trays are brown in colour, and can be filled with water (use blue food colouring to enhance the exercise, as we have done in these photos). Each tray has a recessed handle on either side for easier carrying. The trays measure about 22 cm square (about 8.5") and stack neatly on top of one another for easy storage. This material illustrates the same formations as our Sandpaper Land Form Cards.