This set includes five pairs of land form cards on 3mm thick hardboard, measuring approximately 19 x 20 cm (about 7.5" x 8"). Each pair shows a different land form and its opposite, such as island/lake, gulf/peninsula, strait/isthmus, bay/cape, system of lakes/archipelago. The land is represented by a green sandpaper finish and the water is represented by a blue painted finish. The set comes with a divided wooden box for storage and display. This material illustrates the same land and water forms as our Land & Water Form Trays.