The material is a tough, white, premium vinyl sticker, good for almost any very flat surface. Windows, smooth walls and laptops are ideal; bricks and wood are not. They are removable and can be taken down with little to no residue, but they're not designed to be re-stuck. Outdoors they'll last for at least18 months. While water resistant, we advise to hand-wash only. Dimensions are approximately 3.8 by 4 inches