uni-ball Inkview whiteboard markers use specially developed ink which produces smooth writing and is easy to wipe off whiteboards. The transparent inkview barrel allows you to easily see how much ink remains - no more running out during that important presentation. Producing a solid 1.8 to 2.2mm medium line from a bullet tip. oack of 4 pens. 1 x Black, 1 x Blue, 1 x Red and 1 x Green.