Uni-ball PWE-5M Liquid Chalk Pens. Multi-Purpose Wipeable Coloured Markers for Blackboards, Chalkboards, Whiteboards, Glass, Mirrors, Plastic, Windows, Metal. Medium Tip. 4pc Halloween Set Brand: uni-ball Writing instrument form: Marker Pen Colour: multicoloured Ink colour: Black, White, Fluo Orange, Violet Material: Plastic Point type: Medium MULTI-PURPOSE - Chalk Marker is a multi-purpose chalk and glass marker that can be used indoors and outdoors. RESISTANT TO RAIN - can be used on non porous chalk boards, glass and metal. It is the ideal for the hotel, catering and local shops trades. NON-TOXIC - Safe for children to use. ERASABLE - Simply remove with a damp cloth. VIBRANT COLOURS - Very rich in pigments provides results of incomparable density.