These egg magnets cannot be used on glass boards as they are not strong enough

Stærk pottemagnet med indvendigt gevind (M3)

As a secondary test

The hook magnet is only magnetic at the bottom and has the strongest pull on a horizontal surface

Manufacturer: 3M™

Power magnet, Ring 8x2x6 mm. hyldeforkant These egg magnets cannot beStrong power magnets with a hole for a wire etc. Made of neodymium. Diameter: 0,8 cm. Height: 0,6 cm. Hole size: 0,2 cm. Strength: approx. 2,4 kg. Sold individually with large discount rates from 10 pcs. This magnet is great for projects where you need a strong magnet that doesn't take up so much space. E. g. for the curtain strings if you want to attach them safely to a metal piece on the window frame or door frame so they don't hang loose.