The magnetic strength is strong enough to store four markers in general.
A reason for a non-sticking marker holder might be the surface of the whiteboard. If you are using a non-Legamaster whiteboard it is possible that the surface of the used whiteboard is not strong enough for our magnetic accessories. Please test the magnetic marker holder on a surface with an higher iron content.
If you need marker holders with a stronger magnetic strength, please use our magnetic accessories for glassboards.
Marker holder with a standard magnetic strenght: 7-122000
Marker holder with neodym magnets for glassboards: 7-122100