They are made of plastic with a small strong neodymium magnet at the bottom

Very strong neodymium & steel pot magnet with a rubber coating and internal thread (M6)

Looks like small Beetles from VW

As an example

To achieve the strongest pull we recommend the magnet be used on a horizontal surface

Magnetbånd Gult, 40 mm. boardmarker mix They are made of plasticYellow magnetic foil, available in 1 metre rolls. Width: 4 cm Thickness: 1 mm Length: 1 metre. Colour: Sunny yellow. Strength: approx. 80 gr sq. cm. Please note: Magnetic foil is not suitable for magnetic glass boards. Magnetic foil is incredibly flexible. Here are some of the things you can do with magnetic foil: Cut with regular scissors. Writable. Cleanable. You can also use magnetic foil for marking whiteboards, storage shelves, etc. The magnetic