Dust free, odorless, and washable from all non-porous surfaces. Writes on White boards, & chalkboards and is easy to wipe off. Writes on paper, poster board, wood, and cardboard for a semi-permanent color. Writes on glass, mirrors, and windows. Wipes off with a dab of water. No odor no caps and writes on almost everything. Simply twist to move tip up and down. 24 colors.