You can't take 2 of these magnets and put them opposite each other - they have the poles facing the same way and will therefore repel each other - use a similar sized neodymium magnet (power magnet) or a piece of metal to counter this recessed power magnet instead

so they will do something extra on a boring whiteboard

Separate the 2 parts from each other (magnet and steel)

Strength: approx 3

UNI Chalk Marker, Sort (1,8 - 2,5 mm.) knivskinne You can't take 2 ofBlack Chalk Marker from UNI for smooth surfaces like glass. Model: Black Chalk Marker Medium Line, Uni PWE 5M. A chalk marker is "fluid chalk". You need to rub it off with a wet cloth to remove your text or drawing from the window, glass board or chalk board again. But this is an advantage to this product as this makes sure that the writing doesn't come off easily in wet weather etc. Even when wet, you still need to rub it off. Color: Black. Contains: