Stabilo Ohpen Perm Markers , Set of 8 , Multicolored Present with confidence - great presentation tools that will not smudge important slides or transparencies Versatile - they will also write on almost any hard surface, so are perfect for any task you would normally need a marker for Permanent and nonpermanent - a choice of either water soluble or permanent ink to choose from in each color (black shaft indicates permanent ink, gray shaft indicates non-permanent, water-soluble) Long lasting - a cap-off time of up to 3 days Variety - available in three tip sizes: superfine (.4Mm), fine (.7Mm) and medium (1Mm)