These are disc magnets (12 x 2 mm) with an adhesive force of approximately 1 kg, shrink-wrapped into a round PVC cover. They can be sewn into clothing or used in wet surroundings without rusting. A sales unit contains a strip with 10 magnet pairs, which equals 20 individual magnets.
Thanks to the plastic covering, the magnets can be washed in the washing machine. To avoid damage to the machine or fabrics you should wash clothing with magnets in a laundry bag on the delicate cycle (no spinning). Do not wash magnets hotter than 80° C, as this will cause the magnets to demagnetise.