Small Metal 2-Post Power Magnet with Adhesive. 1 1/2" x 3/8". Magnet/Metal/Nickel Plating. Surface Gauss rating: 3340. Gauss rating is magnetic strength rating. The higher the number the stronger it is. This magnet should not be used with a pacemaker. All JDS magnets have adequate strength to be used as badge attachments. Foam tape adhesive is on the side without the magnet.