100 Round Self Adhesive Magnetic Circles .5" Diameter 4 mil Magnets Arts and Crafts School Magnet Dot Tape New Cute Self-adhesive 100 Round Magnets These magnets are black and measure 1/2 inch in diameter and are 2mm thick. They have a peel off backing for you to stick to things, or you can apply glue for a better hold. They are lightweight, not heavy duty. Perfect for arts and crafts, holding lightweight papers together, etc. Great to hold your children's test on the fridge, or an important bill or document you don't want to forget about!