Cartridge ink for "board master" with deep brush strokes that can be seen even from a distance. Compatible with all types: medium / broad / log / chisel / extra thick Cannot be used with the Board Master S Series. Write dark and clear. 3 features of the Economical Whiteboard Marker "Board Master". 1: Dark brush marks that you can see clearly even from a distance. 2: Stable stroke concentration from start to finish. 3: The ink and tip can be replaced for economical.