From the manufacturer:
This Journaling Set pairs the Sarasa Clip with coordinating colors of the Mildliner, for beautiful highlights and creative embellishments. Sarasa Clip pigment ink is fast drying so no smears or smudges when used with the Mildliner. Mildliner colors are soft and translucent, great for layering, highlighting and drawing. This 6.25x5.5x.5 inch package contains seven Sarasa Clip pens and seven Mildliner markers in assorted colors. Conforms to ASTM D 4236. Imported.