【Magnetic Clips Heavy Duty】：Magnetic clips are ideal for holding notes，lists and photos on your fridge，magnetic whiteboard or other metal surfaces..【Quality Material】：The magnetic clips are made of sturdy metal and strong magnet,you can use them for a long time, they are not easy to damage or rust..【Excellent Eesign】The black object you see is not a magnet. It is a plastic protective shell. It protects your fridge from scratching, and the magnet is inside it. In addition, the overall design of this clip is perfect, beautiful and lovely..【Need Attention】You need to make sure that your refrigerator doors are made of metal. If not, they can't hold magnets. Sometimes the surface of some whiteboards is very thick, which will also reduce the magnetism of the magnet. If you can't use the magnet clip in this case, you can contact us to return it , and we will deal with it as soon as possible..【Classroom Supplies】The clips with magnet are good classroom organization,they are useful teacher supplies.