25/30/50mm Magnetic Field Viewer Magnet Poles Testing Card Magnetism Area Observation Film Card Magnet Detector Pattern Display describe: This project is easy to use. place the card on the of a magnetic material and it will display a patterned magnetic field. Great for personal or scientific research. It can help us study magnetic fields that we cannot see. It can be used for quality control, product demonstrations, reverse engineering, certification and educational purposes. Small and portable, light weight, easy to carry. A great educational tool to our interest in science. Magnetic Field Viewer is a -encapsulated film that allows users to view static magnetic fields. The highly flexible film is suitable for magnetic s with any convexity or cavity. Specification: Size: 5050mm 2525mm 3030mm Color: yellow Effect: True Color, Gray Quantity: 1 piece Package Included: 1 Magnetic Field Viewer Transition: 1cm=10mm=0.39inch Due to manual measurement, please allow 1-2 cm error. Make sure you don't mind before bidding. Due to differences between different monitors, the image may not reflect the actual color of the item. Thanks!