Our needle minders are made of enamel pins and extremely strong neodymium (rare earth) magnets. The enamel pin has two magnets- one glued to the back of the pin and the other that will go on the back of your canvas.
To use, slide the magnets apart and then attach to the canvas of your choice. It measures a little less than 1 inch by 1 inch (slightly smaller than a quarter).
Note: Rare earth magnets are strong and are choking hazards. Just like all small objects, please keep this away from kids & pets! :)