User information: Adhesive Surface Please make sure that the surface to which you are applying the adhesive side is dry, clean, and adhesive-friendly. To obtain good adhesion starting with a clean surface is essential. Magnetic Surface The surface on which you plan to stick the magnet should be magnetically receptive. Please note, such surfaces as aluminum or copper are NOT magnetically receptive. Pull Force X-Bet Magnet Magnetic Dots are meant to hold lightweight objects, for example, pictures, postcards, small crafts. They will hold up flat items weighing 60-90 grams. If you wish to hang a heavier object, please make sure you use 2+ magnetic dots.
eBay