Perfect for Writing on Non-Porous Chalkboards, Chalkboard Labels, Windows, Metal, Plastic, Glass and Any Other Non-Porous Surfaces. Rain Resistant so Are Suitable for Indoors and Outdoors Use. Can Also Be Easily Removed From Non-Porous Surfaces Using a Damp Cloth. Available in a Range of Bright Vibrant Colours Including White, Black, Blue, Red, Violet, Fluorescent Orange, Fluorescent Green, Fluorescent Pink and Fluorescent Yellow.