This STABILO OHP Pen is an overhead projector pen with a fine tip. Writing in permanent ink, this STABILO OHP Pen can be used on most smooth surfaces, and are ideal for writing on clear acetate for use in overhead projector presentations. These OHP Pens have fine tips, handy pocket clips, and if you accidentally leave their caps off they will take 3 days to dry out. They Feature a non-slip grip for added comfort, these acetate pens enable easy, tension-free handling.They are perfect for presentations at work or university, or for teachers using projectors in the classroom.. Writes on almost all smooth surfaces. STABILO quality for a variety of uses - from fine writing to clear marking . Black shaft indicates permanent ink . Grey shaft indicates water soluble ink . Ideal for any transparency. Non slip grip zone and practical clip. High Cap off time of up to 72 hours!