Ecology Yes Dry Erase Markers After the ink becomes diluted, knock it a few times and it will restore its concentration and write vivid. The tip is pushable in the back without pressing the nib, so it will not hurt or leave a sticky spot. Fine point for smaller writing Line Width: 0.05 inches (1.3 mm); Round core/fine line; Color: Blue; Material: Cap/foreshaft: PP; Knock part: POM