Pilot FriXion Set2Go Rollerball Pens have erasable thermo-sensitive ink which allows you to erase any mistakes you make using the rubber on the end of the pen. These rollerball pens are ergonomic and comfortable with a grip to help you control your pen. To help you do your bit for the planet, they are made of 50% recycled material and are refillable. The plastic case doubles as a desktop pen holder to keep your pens organised. This pack of four pens includes one black, blue, red and green pen.