Magnetic Field Viewing Film Sheet Magnetic Field Display Magnetic Field Demonstrator Magnet Pattern Detector Reusable and Automatic Recovery Placing magnet behind magnetic flux viewing film changes color by magnetic level. Color change according to magnetic intensity 50-100G Orange 100-150G Yellow 150-250G Light Green 250-300G Green 300-500G Dark Green 600-800G Blue 900-1000G Dark Blue Film thickkness (m): 150~200 Heat resistance test: 75 48H Coonstant temperature and humidity test: 60/80 48H Outdoor exposure test 48H color:As shown Material:composite material size:200 x 300mm Package Contents: 1 x magnetic viewing film Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.