The Niceday Retractable gel ink rollerball pens provide a smooth, crisp finish (0.5mm) when writing at work or at home. With great comfort and control, these rollerball gel ink pens are an ideal choice for all your writing tasks. The rubberised grip is wide and contoured to help reduce cramps and other hand aches. Convenient clip gives you easy access. Simply attach it to your pocket, binder or travel bag for use whenever you need it. Conforms to ASTM D4236.