The ClickArt Retractable Markers from Zebra feature an innovative ink that prevents the pen from drying out by drawing moisture from the air.
With the newly developped ink, the ClickArt marker is a water-based color pen that can be used by clicking the top. This saves you the trouble of opening and closing the cap and allows you to easily use multiple colors.
Also available in other sets.
The full set of 36 includes the Standard, Light and Dark Sets.