Dixon dry erase markers write on all types of whiteboards and non-porous surfaces, including glass. Opaque inks flow smoothly and evenly on the surface. They wipe away cleanly and easily with a cloth or eraser. Wedge tips provide a variety of strokes. Vented caps conform to small parts specifications. AP certified, non-toxic. Each pack includes 12 markers. Markers write on all types of whiteboards and non-porous surfaces. They remove easily and completely. Wedge tip for variety of strokes. AP Certified, non-toxic. 12 black markers. Age: 8+ years/Grade 3-12