Mitsubishi Rainbow Hydromarker- Dermatograph Pencils
"Peel-off" style grease pencils that make water-removable marks on a variety of surfaces including glass, metal, and plastic. Commonly used in medical fields for making easily-erasable marks on skin.
No sharpening required, simply pull the string at the tip to remove the paper wrapping and expose more of the pencil.
Sold individually.