Encourage students with positive sayings and decorate your class at the same time. Clingy Thingies are made with a special cling technology. They are not sticky to the touch, yet they stick to any smooth surface and can be easily removed. You can even use water to rinse lint or dirt off the back surface. Clingy Thingies can be used again and again without leaving any mess or residue. They also feature a write-on/wipe-off surface. Set features 20 pieces; largest measures 16-3/4 x 2-5/8". Not recommended in areas exposed to extreme heat or direct sunlight; such as windows.