50 * 50mm Magnetic Field Viewer Card Magnet Pattern Viewing Film for Scientific Observation Use Description: This item is easy e, just place the card on the surface of the magnetic material, and it will reveal a magnetic field of pattern. Great for personal or scientific research and it help us study magnetic fields that we can't see. It can be used for quality control, product demonstration, reverse engineering, authentication and educational purposes. Compact and portable size, lightweight, convenient to carry with you. Wonderful educational tool to stimulate our interest in science. Features: Just place the card on the surface of the magnetic material, and it will reveal a magnetic field of pattern, easy e. Great for personal or scientific research and help us study magnetic fields that we can't see. Can be used for quality control, product demonstration, reverse engineering, authentication and educational purposes. Compact and portable size, lightweight, convenient to carry with you. Wonderful educational tool to stimulate our interest in science. Specification: Condition: Color: Dark Green Product Size: Approx. 50 * 50mm / 2.0 * 2.0inch Product Weight: Approx. 1g Package Included: 1 * Magnetic Field Viewer Card