Feature●Comes with (4) 5-Pound bottles●Professional grade semi-permanent waterproof marking chalk●Exterior applications include concrete layout, roofing, metal fabrication●For weather and water resistant lines that hit and stick for a long time, but will eventually wear away naturally●Made in the USADescription Prochalk semi-permanent for weather- and water-resistant lines that hit and stick for a long time but will Eventually wear away naturally. Exterior applications include concrete layout, roofing, metal fabrication.