Set of 4. These are painted with acrylic paint on commercially available clear (blue) magnets and finished with varnish. Strong magnets for attaching documents, memos, photos, etc. to refrigerators, lockers, and whiteboards. While the paint is sealed and varnished to adhere, it may peel if dropped or strongly snagged. Diameter: 4 cm Materials: Magnet, Polystyrene The photo shows the finished product with varnish applied.