Retractable design offers one-handed operation with no cap to remove or lose. Low-odor ink formula erases cleanly and is ideal for classrooms, office and home. Patented seal design ensures the non-toxic ink never leaks or dries out. For use on whiteboards and most non-porous surfaces. Pop-in refills are available. 2.0mm bullet tip. The 6-count assorted set includes black, blue, red, green, orange, and purple. The 3-count assorted set includes black, blue, and red.