The Petattsu adhesives are like gelatin colored dots that are easy to peel off from a variety surfaces. The gummy glue spots are acid free and can be used for photos, notes, kitchen recipes, posters, and more. The product can be reused for as long as the stickiness will last, making them very useful for posting different recipes on your kitchen cabinet for example. Or, you can hang your children's artwork on their door without having to worry about tape damage or holes. They work best on clean, hard surfaces. Avoid hot surfaces (exposed to sun or over 104 degrees F), dusty, oily or uneven surfaces. You can try the adhesive on an inconspicuous place to test it in advance. Product dimensions: 1 cm in diameter for Medium size, 1.4 cm in diameter for Large size. Approximately 0.2 mm thick.